Deletion of Inspection Plan

Gurus,

I need to delete task list (Inspection Plan) for a material. This material has only one unprocessed inspection lot (I have checked thoroughly) which however is cancelled (status - LTCA):

I have also checked table QALS for this material to make sure that there is no inspection lot w/o UD:

According to me this should not cause any problem while deleting the inspection plan of this material. However when I try to delete the task list completely using t-code CA98, I get this error ("Task list is still used in the inspection lots"):

Any input on this will be highly appreciated.

Thanks

Deep