SNAT hangs system in SMP mode (kernel 2.4.21)

[Diederick van Dijk]

Hi,

Yesterday I upgraded my system from one Pentium III 450Mhz processor to 
two Pentium III 450 processors. This system is my gateway to the internet.
After upgrading I recompiled the kernel (2.4.21) into SMP mode.
Unfortunately this wasn't a success. After a few minutes my system hung. 
After some searching I'm realy sure that my SNAT rules are the problem. If 
I get my email on an other PC with no other IP activity on my network my 
gateway immediately hung. Retrieving email uses a SNAT rule.
So I recompiled my kernel uni-processor and the problem was over.
Is this a known problem ? How do I fix this (MASQ rules are not the 
solution) ? If someone needs additional information please ask.

System specs :

- 2 x Pentium 450 Mhz
- 256 MB SDRAM
- kernel 2.4.21 (not the stock Mandrake kernel)
- iptables 1.2.7a
- Mandrake 9.1
- 9x SNAT rules

Thanks in advance,

Diederick