dont have the Gmail M icon on the toolbar..i try to add it, it says OK..then it doesn't show. all other buttons show up fine when added...?

[fixed spelling]

try uninstalling the toolbar and installing it again

Try removing all you other buttons and leave the Gmail button marked.

If you still don't get the Gmail button, do what Danny suggested above.

tried both of these things--no luck

Then i dunno.
Try contacting them:

IE:
http://www.google.com/support/toolbar/bin/request.py?contact_type=problem

FF:
http://www.google.com/support/firefox/bin/request.py?contact_type=problem&submit=Continue

Notify us with further information.