Question : Exchange 2007 Transaction Logs

Similar to another post I have read on here (but doesn't answer my specific question) we are experiencing a large amount of transaction logs building up.
My colleague who deals with backup is having some issues with Exchange backing up properly at the moment and as a result i suspect that it is because of this reason that the transaction logs are not clearing, and are already up to 32Gb (on a 50GB) disk.
Is it possibly to delete logs that are more than a couple of days old?
Other than resolving the backup issue, is there anything else I can do to keep disaster at bay in the meantime?
Cheers,
P.

Answer : Exchange 2007 Transaction Logs

Thanks for the update. This is just for everyone's future reference. When LCR is enabled the truncation of the logs by Exchange aware backups means that the log cannot be deleted until the LCR registers the log as being successfully copied to the LCR location.

Exchange Backups and LCR
http://technet.microsoft.com/en-us/library/aa998195.aspx