My server got hacked through an outdated Geeklog script. I need to install a fresh copy of the script, but my databse hasn't been upgraded and my host won't let me reinstall the old version because of the security hole. Is there any way to install the latest version and import/convert the old database?

Sure, that's how all the updates work.

Import the old db backup, install the current version, call up the install script, select "upgrade" and follow the instructions.

bye, Dirk