No, this is not normal. Kill the MVT process from Task Manager then download and run Security Scan Plus from here (ignore the bit about getting online help for $89). It's a small fast tool which scans memory and processes for malware, but more importantly gives you a quick overview of the current state of your antivirus installation. Tell us if it finds anything out of the ordinary. Meanwhile I'll go and check - there have been one or two other reports recently of MVT getting stuck.