Hi Celine
The only time I have ever had to re-log in was when Avalon reboots the forum server, or it goes down.
Might I suggest you pick up something fairly heavy, and not too expensive, then chuck it at your dear husband's head. Then in your best shrill voice suggest something like...
"Fix this!!! N O W ! ! "
In all seriousness, I am not sure why some folk keep getting logged out, except... when you do log in, there should be a check-box there that says, "Keep me logged in". If you see it next time, make sure it is checked.
Fred