EDIT commands disabled - help!!

I am using dreamweaver 8 and suddenly all of my edit commands (cut, paste, copy
etc) are greyed out and don't work. I can add text in code and design view, but
cannot cut or copy it and can only delete it by using the delete key. This
happens on all pages that i create whether they have a template or not.

Is this a known bug? Have I accidently turned on an option to not use these
commands? I have checked in other applications and all edit commands work just
fine so it doesn't seem to be a windows thing.

thanks in advance