<< Branched from an old discussion about photo gallery not opening >>
I had a similar problem, only it was because i was in the phone deleting files that i thought i didnt want. UGH! I think mine was due to facebook and not syncing. My gallery would work, but the widget on the homescreen seemed frozen and when i tried to look at picture thru it, it said there was an error.
I deleted facebook and then installed it again, somehow, getting better updates. I also took the widget off the homescreen for a little bit. After a reboot of the cellphone, and an update of facebook and new SYNCS, suddenly it is working again as it once did.
I did NOT want to do a hard reset, it took along time to tweak my settings as i wanted them, so i opted out of it.
Hopefully you have better luck than i did. It took me like a week to figure houw i was going to go around doing a hard reset.