I tried to access the site with Contribute and got the warning message that "the site is being administered by a newer version of Contribute" and I can't connect to our site. Any ideas?
Yes. I recently updated my version of Contribute from CS3 to CS4 and set the compatibility to "Compatibility Mode" (requiring all users to upgrade to CS4) as opposed to "Transitional Mode" (allowing users to use earlier versions like 3 and CS3). I've corrected this setting and you can now access the site.
FYI - the confusion came when I had asked what version you are using. You correctly read off "version 4" and I took it as CS4. As it happens Contribute CS3 is version 4 and Contribute CS4 is version 5. Confusing but true. - Dominic