Save As: Save button in dialog box grayed out

I'm working in Photoshop 7 for Mac. When I clicked Save As on images that were created before today, the dialog box to name the new document came up, but no matter what I did, the Save button remained grayed out.
I had a number of programs open because I was altering and sending 2 or 3 images at a time by email. Everything was happening very slowly, so when I noticed this glitch, I closed everything and turned computer off. When I turned it back on and reopened Photoshop, it was just the same.
I'm stalled until I can fix this. Do I need to reinstall my images? or my Photoshop? or start over with a newer version of Photoshop?

Trash your preferences

this is covered in the FAQs

Boku, thank you for your reply. I overlooked that question as a possible answer. However, I searched my harddrive and received a list of libraries and preferences for a lot of things, but none for Photoshop came up. In the Photoshop applications folder I found Presets, is that what I should trash?

Do NOT trash your Presets folder.

Hold down Shift-Option-Command as you start up Photoshop and you should get a dialog asking if you want to reset to default preferences. This is covered in the FAQs and your Help files.

<http://www.adobe.com/support/techdocs/312917.html>

Thank you all for pointing me in the right direction. Saga: I reset preferences. Didn't work. Reinstalled Photoshop 7.0. Didn't work. However, I then just tried to save the image in other places and found that if I backed out of the specific folder which was in my artworks folder, backed out of that which was in my documents folder, the save button came alive again. Maybe I had maxed out the amount I could put in those folders? Whew. I'm up and running again - I hope.

It's a permissions issue. you were most likely being saved from destroying your originals.