Admin Pages not refreshing!

When I do something like login or activate or decactivate a plugin or change a user option or change templates, I get a blank page. In some cases hitting “enter” on the URL line gets me back to where I want to be, in some cases I have to edit out the GET portion of the URL and then it works. The actions (logging in, changing template) do occur. I am not sure if this is PHP bailing or what, and I’m not sure if it is a database problem.

Any suggestions?