Diane,
I split your topic into a new one, as the other topic you posted in didn't mention anything about JFolder::create issues.
If you're seeing that, it's likely a server configuration problem. Can you go to System Information -> Directory Permissions and make sure that all directories are labeled as "Writeable", specifically the tmp directory? If they aren't, you'll need to fix that on your server to install extensions.
Let us know if that helps,
Alex
JFolder::create error
