I've had the same problem too. I thought it was just me. I have to restart to get them to show up but like others have said, it takes a while to start the Droid back up.
I found that if I take a pic and lets say send it somewhere or not close out the properties in the camera or click the done button that this happens. Usually fixes it by going back into the camera and make sure its on just the snapping section (like where the big preview is and where the snap circle thing is bottom right) then press home and it then shows up in the gallery 100% of the time for me
I was having this problem also but not with the camera. For me it was only images that were downloaded from apps or the internet. A reboot worked for me after reading this thread, then I downloaded SDRescan for good measure. Thanks.
I've had this issue since I bought the Droid back in Dec 2009. I rooted and I had the same problem. I got Froyo with BB 0.1 and had the same problem too. Annoying for sure, especially when I try to show people pictures I just took and I have to go into the camera to get them.