The plague package does "Requires: python-sqlite", which is a capability provided by the "python" package, and it does "import sqlite" in the plague-server User.py and DBManager.py files, but Python 2.5 includes only a "sqlite3" module. Additionally, it is API incompatible with the old "sqlite".
Rudimentary sqlite3 support for plague 0.5.0: http://mschwendt.fedorapeople.org/plague-0.5.0-fedora8.patch
This bug also shows up in Fedora Core 8, not just the "bleeding-edge", AKA Rawhide.
Changing version to '9' as part of upcoming Fedora 9 GA. More information and reason for this action is here: http://fedoraproject.org/wiki/BugZappers/HouseKeeping
Btw, the sqlite3 patch for plague 0.4 is here: http://mschwendt.fedorapeople.org/plague-0.4.4.1-sqlite3.patch