I have a task in Outlook 2007 that I can not delete, mark as finished or
anything else. It is locked tight.
It gives me a reminder everytime I open Outlook and it is quite annoying.

If I try to set it as finish or try to delete it Outlook gives the following
message (translated from Swedish to English):
"The Assignment could not be finished. One or more parametervalues is not
valid."

Any suggestions, I have tried to search for an answer on this forum, on
microsoft.com and with Bing/Google without luck.

A big thank you in advance!