While exploring Relic Castle, I got a "ping" from the Dowsing Machine; however, my screenshot didn't reveal any item where I was standing. What do I do to get this hidden object when the usual "press A" doesn't work?

I'm not sure whether I should post here or start a new thread about this. But the fact that I have doubt probably means I should post this here:

After beating the Elite 4 once in Black 2, the only thing I've done is Black Tower and Battle Subway. Before moving on to XY, I want to finish up every other sidequest, etc. in the game. Can you guys name as many things to do after story mode?

I'm not sure whether I should post here or start a new thread about this. But the fact that I have doubt probably means I should post this here:

After beating the Elite 4 once in Black 2, the only thing I've done is Black Tower and Battle Subway. Before moving on to XY, I want to finish up every other sidequest, etc. in the game. Can you guys name as many things to do after story mode?

Well, there's the south-eastern side of Unova, as well as the area around Icirrus City and Twist Mountain where you can battle very powerful trainers and catch even more Pokemon. There's also a tag battle with Cilan, Cress and Chili in Striaton City, more battles you can do at the Pokemon World Tournament, the Dropped Item sidequest involving Yancy/Curtis, you can build up your Join Avenue, and also catch several Legendary Pokemon including Latias/Latios, Heatran, the Lake Guardians, Reshiram/Zekrom, Kyurem as well as the Regis, and if you have all three Regis in your team you can also catch Regigigas.

Is it possible to get a Shiny from someone in this game?

can every pokemon in the field egg group learn any egg move due to smergle? Or is it just for combos like, eevee's moves are helping hand, tackle, tailwhip, and detect (the egg move)

Not every move of male Smeargle will pass on the offspring.
For example a male Smeargle knowing the move Hydro Pump will not pass it to an Eevee offspring.
But if it sketched the moves like Yawn or Wish it will pass to the Eevee offspring.

If the Smeargle knows a move that the offspring can learn only by breeding, the offspring will be born knowing the move.

So I do a lot of breeding, and thought it would be worth while to get myself a nursery in my Join Ave to help things along.

It has been extremely helpful, as I can basically go from being handed an egg to it hatching in about 3 minutes (even with 41 egg cycles). This also means I can reset for egg IVs/natures right? Because the IVs and natures are generated when you are handed the egg?

Nay nay. I saved right before getting the egg from the day-care, then flew to Join Ave and hatched it at the nursery. Checked the IVs and they weren't what I wanted, so I soft reset. Repeated the process and...

got the same exact nature and IVs. Not gender though...

So I decided to try again and hatch the egg normally. It ALSO had the same nature and stats.

So what's going on? I thought everything about an egg was determined when you receive it from the daycare, not when it was first generated in the day-care. Did this change for gen 5 or something? Or did I encounter a glitch somewhere along the way?

Here's an interesting question.

SO I'm trying to breed Metagross to hatch a good Beldum with proper IV scores and Adamant nature. But since both Ditto and Metagross are genderless Pokemon, I can't take advantage of the mother passing down it's nature to offspring.

Anyone has any tricks to breed Beldums with only Adamant Nature?

Would the actual species being bred be the one that is considered female in that instance?

I don't have a precise answer for him,
but still my answer still stands for Pokemon like Metagross,
are able to pass their Nature with Everstone.

Can the move tutor teach moves to Pokemon that never got high leveled enough to learn them in previous forms? If not, what moves of Pokemon that evolve via stone/trade is irreplaceable?

My sincere apologies if this is in the incorrect forum/thread, but is the Global Link website down for anyone else? It's been in "maintenance" for 3 hours or more now and I was wondering if this is a usual thing; i've barely just started doing Dream World yesterday.

Edit: Just found the Maintenance page from the official site, and it shows Maint. being from 3 am to 7 am Tuesdays EST. Will that still be happening in light of this downtime?

Japan and Korea: Tuesdays 4 p.m. to 10 p.m. JST/KST
US: Tuesdays 2 p.m. to 8 p.m. EDT
UK: Tuesdays 7 a.m. to Wednesdays 1 a.m. UTC
Australia: Tuesdays 3 p.m. to Wednesdays 9 p.m. AWST

The Pokémon Global Link will be closed for maintenance from Oct. 1 to 12, 2013. After this maintenance, users will not be able to sign up for new accounts, and players will not have access to the demo nor be able to add additional games to their accounts. On Dec. 10, 2013, players will no longer be able to tuck in new Pokémon, although Pokémon currently tucked in can be played with and woken up. On Jan. 14, 2014, all services offered by the Global Link will be shut down, except the player's ability to untuck Pokémon. This means that players will no longer be able to change their C-Gear skin, Pokémon Musical song, or Pokédex skin.
The GTS will not be affected by this closure, except that the trade history will no longer be viewable. Random Matchup Rating Mode will be shut down, although Free Mode will still be available.

Thanks for answering my earlier question. Noww another opinion based question. I pretty much know the answer already, but I need someone's feed back.

I got myself a teddiursa, and I want to EV train it. But it's a Hardy nature, which I cannot get any bonuses from it's nature. It has a nice IV score, but it can be better with patience. It's IV scores are:
HP: 14
Attack:23
Defense: 20
Sp.Def:14
(It has a high special attack IV score of 22, but why does it need it?)

So I ask, What should I do with this Pokemon? Should I EV train, and live without the 10% bonus to one of it's main 3 stats?

Should I breed this Pokemon, and get a Adamant/Impish/Careful nature (and pray that I get a Pokemon with IV scores this nice)?

Thanks for your answer. Turns out that my Teddiursa has an ability which I do not like. So either way, I need to breed it in order to get the "Guts" ability anyway.

My Ditto is Serious Nature, which means I'll either need to recatch a Ditto with the proper nature, or just keep breeding Teddiursa until an Adamant one is born.

So my next question is: What is RNG?

RNG is short for Random Number Generator and is what is responsible for how everything in the game is generated. The RNG in Pokemon games can be manipulated so you can obtain the exact Pokemon you want. More info can be found here in this thread. As for what others want when trading, you can browse through the shops to get a feel for what others have and want. Hope this answers your questions. :)