Hmm...
If it says 'it is not a valid text layer' I think the fonts used to make that text layer might not be installed in your system. I'm not saying this is the case, I'm saying this might be the case with the psd files.
Do you get the message when you open ANY or SELECT psd files?
Try making a psd file and put in a text layer into it, then try opening it. Now, do you get this message again?:ughdance: