strange PM issues

WWF ver 9.xx hosted by none other than our own WWF hosts.
I've got the PM setting to 40 max.
That's worked fine for months, even after the move to WW hosting, it worked fine. We have problems with some people who don't clean up their stuff and are always full on PMs and so folks post messages "hey joe your PM is full, empty it!" but otherwise it works. (yes, I'm one of those with a full PM inbox)
HOWEVER, we have at least one person, perhaps another, who say that at 10 messages, others can no longer send them PM.
One of them is a mod, and I verified - asked him to check that he's only got one page of 10 and not 4 pages of 10 equaling 40 and no, it's only 10 in total that he has, yet until he removes some of those 10, no one can send him a PM. We've had a rash of full PM boxes lately, although he's the only one who has spoken up so maybe, just maybe the others really DO have 40. But I know Ron, he doesn't, he's got 10, and that's causing others to not be able to send.
IS there a way to look into this and see what's up? The settings are correct and mine works properly, topping out at 40.

The number of PM's is counted by using a query that counts the number of records that user has, so I can not see how it can go astray for one of your users.

You may want to tell them to empty their inbox to see if that clears up the problem. Also their should be a bar graph at the bottom of their inbox which shows them how full their inbox is and how many more PM's they can receive.

By the way in version 10 the admin will be able to set if new PM's are rejected when the users inbox is full or if it will delete the oldest message and allow the PM to be delivered.