wowser said:
I tried the 'Opt+cmd+p+r' thing that someone suggested. How do I sort out the DS_Store thing?
The former won't help with this particular issue. As for deleting .DS_Store files (note the leading period) your best bet is using Terminal, but if you're not at all familiar with a command line interface, you want to be VERY careful. There are also pieces of shareware that will do this for you or let you see the file so you can delete it, which might be a better idea.
Sorry, you're better off trying Google for specific advice on how--there are a lot of tutorials out there.
Roughly speaking, though, you'll open terminal and type:
cd ~/Desktop [then hit return]
sudo rm .DS_Store [return again, and then enter your admin password]
By the way, did you already try doing a "Repair Permissions" using Disk Utility?