Page.db file size does not decrease after shrink.

IIT,

I have no messages in any of the queues in a router but page.db does not decrease. I have shrunk the page.db multiple times and verified that there are not messages queued (including tmp and rt$ queues). Is this a symptom of a corrupt page.db? Anything else I can try without taking the router down and remove the page.db and transactions files?

(We are using 5.2.5. and persistent queues)

Thanks in advance,

Sir q-alot