1. The messed up map (you know which one) and the one you are connecting it to have the SAME tileset, they can't have the same tileset. Just change it to a different one under "header".
The cave looks fine but did you have warps on BOTH ends?
Example:
1st warp: into Oak's lab.
2nd warp: (in oak's lab) out of Oak's lab.
You get what I'm saying?
BTW unless you are going to use the "light up on flash use" thing for the cave, then make the cave bigger and add more obstacles.