Honestly guys, it's just Sense. Not the memory card, not a leak, not a hardware memory issue, not being low on space. It's just Sense turning to crap upon gingerbread and Sprint is eating pie. Can't fix or won't fix, who knows. I've done and tested and played and edited. My personal conclusion is that Sense has issues with accessing data on SD, but again, that's not a card issue, you can buy 28937289 different sizes or bands, and it's just gonna be Sense each time. Just use another launcher. You can even make those launchers look and act like Sense if you like it that much. Save yourself some time and aggravation. Because apparently Sprint isn't going to fix this if they haven't by now.
Cheers!
PS if any of you were having issues with NoLock no longer working, that's Sense too. Works fine for me now using other launchers.