I have been using coppermine for about a week now and have experienced no problems. Today I decided to add a new gallery and upload some new pictures.
All was well and I selected 5 files from my hard drive and clicked upload. This worked fine and all the files were uploaded. I then set about entering the details for each file (title, description etc)... after completing the details for the second file and clicking ok i was greeted by a "Permission denied" message... i clicked ok and realised i had been logged out.
I logged in again and was messing about in the admin menu when it happened again, the permission denied message appeared and i was yet again logged out.
I opened up firefox and have had no problems at all. For whatever reason IE keeps logging me out... any ideas?
hard to say without a link and test user account, and without being able to look at your IE's settings. Check the privacy tab, check third-party-software like the notorious "Norton Internet Security" suite (and other similar products).