PCIX boot problem

hi..
my pci card works fine in pci and pcix mode in almost all the sysytems
except one or two sysytems where i've a problem during boot up in a
pcix system when i put my card which is pcix capable...

when my card operates in pci mode then it comes up nicely...but when i
try to bring it up in pcix mode it's not coming up....
i tried with analysers and i saw our device responding to config.
transactions properly. Bios then snoops other devices and then again
comes back to my device and this keep on going....so it's in a
continous loop ....
i'm suspecting that there might be some resource conflict but not very
sure and that too in pcix mode only. how can i debug it. i mean how
can i see if there is any conflict or not when it is just stuck...

thx!in advance