Batch, it sounds like Entourage launches properly but crashes when you do a
Send/Receive?
Try the following:
1) If you don't already have a backup of your "Main Identity," make one. Go
to <User>

ocuments:Microsoft User Data:Office 2004 Identities and highlight
Main Identity.
2) Select it; then from the File menu choose Duplicate.
3) Make sure it has a different name than Main Identity
4) Launch Entourage while holding down the Option key. Tell Entourage you
want to open the Database Utility.
5) From the drop down menu at the top of the Maintenance window, choose your
Main Identity (not the backup)
6) Choose Rebuild Database. Note anomalies reported by Entourage, if any.
7) If it completes successfully (which it should), quit the Utility
8) Optional - log out and then back in again. I normally do this as a
matter of course since it kills all open apps and re-opens User preferences.
9) Launch Entourage and see if your problem is solved.
If not...
10) Quit Entourage
11) Go to <User>:Library

references and move the following file to the
desktop (temporarily): com.microsoft.Entourage.plist.
12) Log out; then log back in again.
13) Relaunch Entourage to see if your problem is solved.
If your problems go deeper than this, you'll have to seek help from the
other guys/gals here who know more...
Craig
P.S. Curious: Did you do a "clean" install of Tiger, or did you upgrade an
existing installation?