Please help: File association problem.

[ihbsbA]

So last week I had my first completely random reset.... when the phone finally came back to life I lost a ton of preferences (Push Effect, Inbox tones, etc) and I apparently lost my file associations. Last night I received a png file and I couldn't open it, my phone apparently doesn't know how - it asked me to find a program to open it with, so since I wasn't even sure I could open a png, I had the sender resend it as a jpg and I couldn't open that one either.

This happened to me once before and I hard reset. I REALLY don't want to have to do that even though I have a Sprite backup (and I'm not completely positive that the problem WASN'T there before the random reset) so, how do I fix?
Much Thx