Adobe has provided a fix:
Bridge CS2 returns a licensing restriction error on a computer with Premiere Elements 4 installedEven with this fix, Bridge was still not functioning properly on my system, so I ended up uninstalling and re-installing Bridge. After that, I updated Bridge via the help menu in Photoshop, and seem to be in good shape again.
Special thanks to the folks at the Muvipix forum for following this problem.
Mark