CNF401 CardBus card : realtek_cb reboots

Hi,

I bought a CNET SinglePoint CNF401 Cardbus card a few days ago. It came
with a modified rtl8139.c with cardbus support. I have compiled this
driver and changed the relevant settings in the pcmcia scripts, and the
driver loads correctly. The network is also up and working.

There is one problem, though. Whenever I am downloading at high speed
(eg debian package update) I get the following errors (after setting
debug of realtek_cb to a high enough level) :

eth0: Abnormal interrupt, status 00000011
eth0: Abnormal interrupt, status 00000021

And after a few of those, the system reboots.

Some digging into the code tells me that
0011 = RxOverflow (0x10) & RxOK (0x01)
0021 = RxUnderrun (0x20) & RxOK (0x01)

The page on scyld.com says

0x0010 : Rx Buffer overflow, set when the Rx ring overflows due
to high interrupt latency
0x0020 : Rx packet underrun: this should never occur

Well ehm... it does occur :(

Jun 16 01:41:01 orbit kernel: eth0: interrupt  status=0x0000 new
intstat=0x0000.Jun 16 01:41:01 orbit kernel: eth0: exiting interrupt,
intr_status=0x0000.
Jun 16 01:41:01 orbit kernel: eth0: interrupt  status=0x0001 new
intstat=0x0000.Jun 16 01:41:01 orbit kernel: eth0: In rtl8129_rx(), current
41c0 BufAddr 47b4,
free to 41b0, Cmd 0c.
Jun 16 01:41:01 orbit kernel: eth0:  rtl8129_rx() status 5ee4001, size 05ee,
cur 41c0.
Jun 16 01:41:01 orbit kernel: eth0: Frame contents  01 40 ee 05 00 10 60 5a d0
10 00 c0 26 a9 59 02 08 00 45 10 05 dc 28 89 40 00 37 06 cd 04 c1 be c6 13 c0
a8
00 04 95 ca 04 43 26 61 ^DÑ«^FÖ

The next couple of thousand lines (about 8000 actually) in syslog are
unreadable and seem to be dumped binary code (raw packets ??)

Other info : I'm using a 2.2.19 kernel on a Sony VAIO F801

Does anyone have any idea of what could cause this ? Or, as an
alternative, could anyone tell me where to find a 2.4 driver for
realtek_cb and everything that goes with it ?

TIA
Davy Herben