I'm having the same issue - it started Wednesday. First I couldn't attach pics to a message, did a battery pull and then I couldn't scroll anywhere in the Camera Roll. It just kicked me back to Gallery. Then I started having screen issues in general (couldn't slide bar to answer a call, SLOW response to calendar). However, I also suffered from a random reboot issue about once every 4 days.... I contacted Verizon. They sent me a new phone. This phone has the same issue with the Gallery...not sure what to do with it now.
I'm guessing it was a ninja OTA crappy mini update that broke everything...?
I spent a huge chunk of time experimenting last night and found a fix to the gallery issue. I think its caused by a corrupt file on the sd card that the X's gallery has a seizure trying to read, thus why it boots us out back to the main gallery screen when we come upon the area with the problem.
Here's what I did: Since I noticed that if I hit menu>go to> another date range, then the gallery scrolled fine but as soon as I hit that particular area it would bump me back to the main gallery screen. This told me that there was a file or something right there that was giving it a fit. Soooo...
I went on my computer and after trying moving all my files, reformatting sd and moving them back to no avail... I then just deleted the pix and vids that were around the area that it was having a fit at... I deleted like 63 files and voila! It works fine now... so somewhere in that block of 63 files I deleted was a file causing the issue. I'm thinking of experimenting by adding some back at a time until I find the culprit.. but that can take a while so I'll just leave em on my computer now, Lol!
I sure hope this helps someone!
But.. my.market notifications still don't show up unless I'm IN the market... sooo weird... I don't know if it's device related or what... they tried replacing my phone but the first one they sent me had a PINK hue to the screen and a huge oil slick like appearance on it... so I sent that back and they sent me another one which ended up having 3 white pixels out on the screen in camera mode!!!
Now they're saying they can only send me a certified like new one even though my original replacement was within my 30 days, its not my fault they sent me TWO with screen issues!!! So I guess I'll just stay with this one, for now anyway, I love my X, I just don't love little problems! I wonder if Froyo will work better on it.. I can't wait!!!
I posted this over in the main X issues thread, too:
http://www.droidforums.net/forum/droid-x-general-discussions/60203-official-droid-x-issues-problem-thread-new-post.html