(usr-tc) HiperDSP modems failing?

I run a perl script that checks the call failure rate of the modems on our HiperDSP. It shows that 6 of the 24 modems on one card have a failure rate of over 50%. Any ideas what might be going on and is there any way to disable these modems? Thanks! Mike Moore - To unsubscribe to usr-tc, send an email to "majordomo@xmission.com" with "unsubscribe usr-tc" in the body of the message. For information on digests or retrieving files and old messages send "help" to the same address. Do not use quotes in your message.