Backup Job Hangs

We have been using red-gate's backup pro since July 2013, however after the minor releases at the beginning of December 2013 we have experienced a couple instances where a log backup execution hung and prevented further backups until the blockage was identified and resolved. When this has occurred we have observed the following.

1. SQL Server 2008 was unable to cancel the execution of the job. Manually restarting the red-gate backup service allowed SQL Server to abort the execution.
2. No backup attempt appears in the backup activity history.
3. No log backup file existed before process was cancelled. No log backup file existed after service restart.
4. No errors were reported.
5. The script being executed:

[code]DECLARE @errorcode INT
DECLARE @sqlerrorcode INT
EXECUTE master..sqlbackup '-SQL "BACKUP LOGS [Billing]
TO DISK = ''S:\Log Shipping\<SERVER>\<DATABASE>\<DATABASE>_<DATETIME YYYYmmddhhnnss>_<TYPE>.sqb'' WITH ERASEFILES = 7,
MAILTO_ONERRORONLY = ''address@domain.com'',
CHECKSUM,
DISKRETRYINTERVAL = 15,
DISKRETRYCOUNT = 4,
COPYTO = ''\\ServerName\s$\Log Shipping\<Server>\<Database>'',
COMPRESSION = 4,
THREADCOUNT = 7"', @errorcode OUT, @sqlerrorcode OUT;

IF (@errorcode >= 500) OR (@sqlerrorcode <> 0)
BEGIN
RAISERROR ('SQL Backup failed with exit code: %d SQL error code: %d', 16, 1, @errorcode, @sqlerrorcode)
END[/code]