Please help I'm soo desponded with the following problem:

I have a laptop with 3com pcmcia-Modem/Lancard, a dekstop machine with nforce 2-Chipsatz and network interfaces (2x), both running on Mandrake 10 Community (up to date), on a router that works very well also for a mac that is connected to. It is a DHCP-Router (Alacatel Speed Touch Pro) with IP 10.0.0.138, the computers get 10.0.0.5 and 10.0.0.8.

Not a complicated setup, isn't it, and it was running perfectly under windows and Mandrake 9.2. Because it's an ethernet-ADSL router I do not to have to worry about PPPoE and thelike, I thought.

I now always have interrupts in the internet connection on both machines (sometimes at the same, sometimes at different times) lasting some minutes. Than it changes and connection is reestablished. If I want to ping 10.0.0.138 (the router / default gateway) i then get

connect: no buffer space available.

with dmesg i see neighbour table overflows.

the interfaces are correctly recognized and up.
reconfiguring doesn't necessarily stop a "no buffer"-period (in which the leds on the router may blink anyway and net_monitor may log some received packets anyway as well)

route -n (on both machines the same).
Target Router Genmask Flags Metric Ref Use Iface
10.0.0.0 0.0.0.0 255.0.0.0 U 0 0 0 eth0
127.0.0.0 0.0.0.0 255.0.0.0 U 0 0 0 lo
0.0.0.0 10.0.0.138 0.0.0.0 UG 0 0 0 eth0

I tried with different Kernelversions >=2.6.3.4

I didn't find a way around this problem that really sucks.

I'm VERY grateful for any support and hint.