vpopmail problems with 18000 mailboxes / cdb / vpopmail 4.9.6-1

[ctelles]

Sirs,

We have a machine with 18000 mailboxes in one domain.
We are using vpopmail 4.9.6-1 and when we try to include/exclude or change
one password we get the folowing error :

"could not create/open temporary file".
"Segmentation fault"

Any hint? Maybe I have to upgrade? Is there any limitation for the cdb
file? We are using ReiserFS in this machine.

Thanks

Camilo Telles