I've had this one before, and last time I just re-installed the VZ updater for the Palm 755p.
But the Updater is a major process that requires a cable. Palm has not seen fit to release drivers that allow us to connect our 755p's to Vista 64bit using a USB cable.
So, what other options do we have, Scotty?
I dialed the Palm System Error Log number #*#377# and found that MemoMain.c was at fault, but I didn't know if the Memo database was corrupt or if the Memopad program was hosed.
I considered doing a hard reset, but instead I used the advice in this post: Treo 755p - suddenly resets when I try to open Memo, which was to delete "MemosDB-PMem" from the Internal memory space using the free FileZ Palm app.
It worked. Memos accessible, no rebooting. Vista 64bit to 755p connection problem workaround.
But it was late, and I skipped a step, which made a mess for me. I didn't set the Hotsync conduit for Memos to "Desktop overwrites handheld".
I lost all of my Memo categories and all my hundreds of Memos got dumped into one big pile on the 755p and the Desktop. Oh sheet! What a mess.
Now, I am not certain that if I had set the Hotsync to "Desktop overwrites handheld" that it wouldn't still have messed everything up, but it seems like it woulda helped.