Trouble with Friends list...?

I was just on Siege on one of my oldest accounts and had something quite odd go on..

I logged in where I had parked my char the following Friday.  My main Tower.   He was quickly booted from the house.  I made sure the house was not in decay.. where id be in here yelling my head off that the house was in error decay mode.  Nope that's not it.   I went to other houses I own  he is fine and still on their friends list. Hos own home is fine too. 

What gives???

This is not the first time a house has dropped a friended character off the list... but I thought that bug was fixed.  It has been a while from the last drop.   

No one has access to my accounts outside my son and he wouldn't touch UO for love or money unless I brow beat him to helping me.  So... the bugs back?

Inquiring minds want answers and it fixed.

btw all 54 accounts chars are friended to the main house Id never drop one off it.

Ok I messed up my billing routine to get to the bottom of this...  and got a bigger mystery.

As you all know you may have a house on siege along with your regular prodo shard home.  I got worried someone had hacked me so I sped up the billing....

My production house is fine  the house friends list is great and all are on it as should be.... BUT

on Siege.... the towers Friends , co owner, and guest lits are wiped clean...

I did not do this! house has not been off the paid cycle for more then 30 days.. its one of my main accounts.  ....  OK DEV   answer this one...  how can 1 house of 2 loose its friends list without any of the normal reasons usually at cause? 

Now I got to re friend EVERY account....