samba - May 2003 - SMBmount, T1, GRE tunnel, VERY SLOW file transfers

Hi, my problem is that I have 2 servers on in the US and one in Hungary.
I want to mount a share from the US server here. But file transfers are very 
slow. (Never more than 22kbytes/sec)
The bottleneck is in the US the T1. 
The architecture looks like:

Fileserver -1Gb- Server -T1 (GRE TUNNEL)- INTERNET -100M- HunServer
The ping is 140ms.

It *must* be samba related thing, cos the FTP over exactly the same route gives
me 195kb/sec.

I suppose that the latency is the problem here because of the principles of the
SMB protocol.:(
If it is, can anyone tell me a solution to mount directories remotely. (NFS was
fine, but after some time I realized, when the connection between the two
servers are down it hangs forever. I checked the NFS related forums, and
everyone told me that's how that works...)

Please help, me.
THX
Levi

ps. I tried all the tweaks available on the net.