Gw 8.02 on NW 6.5

My GW Library needs maintenance done on it but when I run GWcheck
standalone, I get a message indicating that there is a similar request
already underway.

There is no activity at all on the POA (I checked the Web portal - no
tasks pending)

When I try to run the same libary job using C1, the task is recognized
by the POA (I can see the message in the Verbose log) but then nothing

How can I clear our whatever old taks in the queue ?