After drush cron --debug I saw the following undefined index errors:

Undefined index: tid userpoints_cap.module:57 [207.5 sec, 264.54 MB] [notice]
Undefined index: tid userpoints_cap.module:59 [207.5 sec, 264.55 MB] [notice]
Undefined index: userpoints_cap.module:59 [207.5 sec, 264.55 MB] [notice]
Undefined index: points userpoints_cap.module:60 [207.51 sec, 264.55 MB] [notice]

Did the taxonomy structure slightly change and has an impact on this module?