ABR for Small Business Server Exchange Logs

Hello all

I am not having problems now but I want to get some stuff clarified before I have problems.

I am running Acronis for Small Business Server. I have turned on the VSS writer for Exchange (turned off my MS by default) in the Registry so now its turned on.
I am using the Hanoi tower scheme for backup
I have turned on VSS in the options (for some reason mine is off by default on backups)
Here is where I am having issues.
The log files are not being flushed from the directory. If I am missing something in this please let me know. I would really like to get the files flushed automatically by the backup sysytem and not by turning on Circular logging.

Thanks!!