VPN between WinXP and OpenBSD (sometimes works and sometimes doesn't)

Hi all,

I have this situation.
I've made a VPN station on OpenBSD box. Some clients connecting to it are
using Windows XP and some are using Windows server 2003. Connections between
Windows server 2003 and OpenBSD work fine, but connections between Windows
XP and OpenBSD sometimes work fine, but sometimes when bigger files are
being copied, on Windows XP pops out the error "the network resource is no
longer available", though ping is working perfectly (there are no any
time-outs) and I still can copy smaller files... I don't understand, what
could be a problem?


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