There is a known issue that could cause this, so if you are using CIPC (soft phone) please try upgrading all of them to the latest version.
CSCsm57884 CIPC - Funny Characters in VarVQMetrics Column in CMR file
Symptom: CIPC produces funny characters in the VarVQMetrics column in CMR files, which causes the CMR files to get stuck in the BAD folder.
Conditions: Seen with IP Commuincator versions 2.1.1 and 2.1.2
Workaround: None
Further Problem Description: MOS LQK Version field inside the VarVQMetrics string is corrupt.