> I did try that and every available option in the monowall gui and still no
> lack.
> Everything looks ok but as I mentioned before continious connections
> drops.
> Like now, I found that VNC does not work in auto mode only in raw mode.
>

MTU issues maybe?  Try dropping your WAN MTU to something like 1400
and see what happens.  May also want to try dropping your client
systems' MTU's to see if that has any effect.

-Chris