There aren't duplex-mismatch and the speed is ok.

1000 Mbps Full-duplex in both sides

Here's a good place to start.

http://www.cisco.com/en/US/products/hw/modules/ps2033/products_tech_note09186a008009446d.shtml

I am assuming this is an ethernet connection.

Generally collisons are the result of speed/duplex mismatches, a bad nic or cable or oversubscription. If you have a open port on your switch, try using that and check for collisions.

Thank you for the advice but I don't use a shared medium. The server is connected to the switch directly.

The connection is a Gigabitethernet.

Thanks

In that case the collisions would be caused by a bad nic or cable. Have you tried replacing the cable or nic? You could also try moving the connection to a \different port on your switch to eliminate the port as the problem.

I have tried this but the problem persist. The problem only exists with the Broadcom NIC because I have others NICS and they don't have any problems