Sorry I couldn't do better with its defensive IVs; this one was traded to me, too, and that's exactly how I got it (including those 5 EVs already in there). I hope to eventually get playing Platinum (working on W2 ATM). I will be hacking Oak's Letter into that game and attempting to catch my own Shaymin, but I'll have to do the battle with Action Replay on so I can check the IVs upon capture (if it sucks, I'll have to repeat the battle). :)
Enjoy the Shaymin. And the eventual Froslass. Don't evolve it, BTW, until you have all the moves you want from Snorunt; Froslass can't learn all of them! :) Crunch at Lv.31 is the last unique move that Snorunt can learn that Froslass cannot, so after that you can evolve freely. You can always use a Heart Scale to get any missed move in Froslass's levelup chain (
see her page at Bulbapedia). :)