Problem with Session tables

Narf is referring to this:

Replace all files and directories in your system/ directory and replace your index.php file. If any modifications were made to your index.php they will need to be made fresh in this new one.

Important

You have to delete the old system/ directory first and then put the new one in its place. A simple copy-paste may cause issues.

The part which starts with "Important" is in a big orange box on the page he linked, so he probably thought it would be pretty hard to miss, especially since I believe it was added specifically because people were having the same issue you're having if they didn't delete the old system directory or use a completely new system directory.

***SOLVED****

problem was with the WAMP testing server. All the time i was focusing on my actual website directory used to upload to the testing server and not the testing server itself. Files weren't being overwritten when i uploaded to WAMP if they had identical names. I deleted everything on the testing server, then uploaded again and it seems to work fine.

Thanks for all your help