Boy, I hope I'm not doing something dumb.
Installed VZWM5 today from a clean machine; install went great. Went to downgrade the phone back to YH25, installed PST, didn't see the I730 because I forgot to install the I730 update for PST

, installed, rebooted, soft reset my phone, got the modem drivers to detect, soft reset the phone and rebooted the machine for good measure -- man, I've tried every combination of rebooting possible, I think.
Every time I set the phone to USB modem and get into PST, doubleclicking on the I730 gets me a "Debug Assertion Failed" error. I found one hit for that error by searching the forum, but the guy that asked never got an answer. I'm pretty much mystified. Any ideas?
EDIT: So I paid a little more attention to the error, and am now more confused. The debug assertion that failed was in dlgdata.cpp, line 43. Now, it's been a while since I did any MFC coding, but IIRC, that has *nothing* to do with I/O at all -- dlgdata deals with the managing of UI objects, doesn't it?