freebsd stable - Mar 2005 - 3Com OfficeConnect Wireless 108Mbps 11g XJACK PC Card

Hi all, I was using  NDIS for a (ath0) wifi 3Com OfficeConnect
Wireless 108Mbps 11g XJACK PC Card under 5.3-stable I upgraded my src
and hove now 5.4-PRERELEASE but now the card is not working well, when
I ping to my gateway I get very high response times and I start to
loose conection. the card acts like if there where a very poor signal,
any idea of what could it be wrong?

regards.