VPN S2S eDir Communication

We are running BM3.8 Sp3 IR2 on NW 6.5 SP3 Site to site vpn. Everything
is working fine, but the Servers behind the remote Site have some
problems with the communication, the communication is established and
after 1 minute lost again and so on.

Running Dsrepair shows problems contacting the remote servers (625),
although Time is in sync and SLP DA is setup at the main site. I am
wondering whether we should use SLP DA on the remote site as well...

Thanks for any input on this...