Hi, heres some ideas:
CRC problems usually comes from things like bad cabling, a bad port, or a bad NIC or duplex mismatch. Check this things first.
I guess that you have a switch that uses errdisable feature. When this feature is used a port that have problems are beeing shutdown. Problems like:
Excessive link change, excessive requests from EtherChannel, Spanning-Tree Protocol problems, and UDLD problems. Check your logs to pinpoint the problem.
If using Etherchannel: check your config and set speed, duplex and channel hard (no nego).
If using SPT: Set root and secondary root hard. Turn SPT off on ports for client.
If using UDLD: check links and modules.
Hope this can be help on the way;
Read more: http://www.cisco.com/warp/public/473/20.html