This discussion may contain spoilers!
I just encountered a small glitch, and after perusing MI forums for a while, haven't run across anyone who's had it, so I'm going to post it here in case it happens to anyone else.
After I've rushed through the blockage and caught up with MacGuillicuddy, I said something to anger him which made him cannon my mast. Winslow suggests we get the mast fixed right away, meaning we should head back to Spinner Cay. Right after Guybrush says something to the effect of, "I know, I know, I'll go to the map," I COULDN'T CLICK ON ANYTHING!
The only thing I could access was my inventory, which didn't do any good in the situation. Basically, my "X" cursor wasn't highlighting anything on my ship.
I saved manually, and restarted my Wii, and once I came back to the game, it was working fine again. Maybe all you have to do is exit the game, but I went ahead and turned everything off and on again.
Hope that helps anyone else.