[imp] The server is still generating the message list

[Dominique LALOT]

Hello

I've upgraded to groupware webmail edition 1.1.3 and got same problem as 
1.1.1
distrib: debian etch + php5 + memcache
Sometimes I cant get the message list.
To do that, drag and drop a mail in a folder, then try to see that folder.

After, you get that blank screen with that warning (it never stops 
untill you log out).
A friend of mine has got the same problem but less frequently

What could it be? Google doesn't show an answer and I don't know how to 
debug it

Thanks

Dom