WG511 loses connection to AP and dies

Hello!

I have a Netgear WG602v2 AP, a Netgear WG511 PCMCIA and an Ovislink
WL-5400 PCI card.

It happens quite often that the WG511 stops receiving data (iwconfig
still shows it being connected to the AP though). When this happens I
can't do anything but ifconfig eth0 down / ifconfig eth0 up (i.e. reload
the firmware) to get it working again.

Sometimes it completely loses the connection to the AP. I then try to
set the essid again, change channels and whatever but it can't reconnect
the AP until I use ifconfig down/up on the interface.

The OvisLink card never loses the connection to the AP, I didn't have
to reset it a single time so far, while I have to reset the WG511 at
least once every hour, sometimes every few minutes.

Signal quality is good (the WG511 even has a better one than the
OvisLink), I have tried to place the PC and the AP at different places
and I have tried different channels but the problem doesn't go away.

Both systems use the same prism54 firmware, same kernel version, same
prism54 module version.

Does anybody have the same problem? Any suggestions what I could do
about it?

thanks,
Max