Odd problem with links dropping

[David Goodenough]

I have a few quite long links, and from time to time the links drop.  They 
then wait between 5 and 10 minutes to restart.  BUT if I eject the card
(they are PCMCIA Senao cards) and then insert it (ifdown/ifup is not
enough) the connection comes straight back.

When the link goes down the signal strength is reported as being 0/92
but when the link is restarted it immediately gets back to something 
like 20/92.  Somehow I think that the driver has given up, and takes
a while to forget the drop and start again.

Is there a more direct reset that I can do rather than unloading the
card and reloading it?

Could it be a firmware problem.  The cards are 1.4.6.  I have tried 
1.7.6 but not in the field yet.

David