Thank you for your post.
When you select "Open Remote", does the remote SERVER show in the local network? If not, then your local machine is having difficulty seeing the remote server, and it may either be a network issue or port issue. (Make sure port 5003 is open).
If the server displays but not the files, then port 5003 may be blocked.
Do you have any other machines running Mac OS X 10.6.2? If so, are they working correctly?
If you set up a new user account, log in to that user account and launch FileMaker Pro, are you able to see the remote files?
Any other information you can provide may be helpful in narrowing down the possible cause(s).