Comodo Backup does not replace zip file


I have been using Comodo Backup for a while now and last week I decided to install the newest version. I have found the following problem:
I backup my Outlook pst file once during the night, at 3 AM. My backup job is configured so that the file is zipped to the network drive. I had no problems with such backup job with previous version, Comodo Backup always replaced the zip file with the new one (of course, I had to close Outlook when leaving my computer in the evening, so the pst file was not locked). It was also necessary to leave Backup opened, I never succeeded to configure Backup to work as a service.
With this in mind, everything worked very well, Backup was opened and replaced old zip with new one every night.
After installing new version I was very satifsfied, because I was able to configure Backup as a service, so the jobs now work even if I am not logged in and Backup is closed. However, I have noticed that my Outlook backup job does not replace zip file anymore. It also does replace zip file when working the ‘old way’ (Backup opened and user logged in).
If I delete zip file manually prior to running the backup job, the job starts to work a should (in user or service mode). The backup also starts to work if I turn the compression off. With compression set to off, there’s no need to delete the files before the backup job starts, the files are replaced OK (valid for user and service mode).

Here’s an excerpt from Backup service log, maybe it will be of any help to you:
15.9.2007 at 3:00:00 | Backup “Outlook” started.
15.9.2007 at 3:00:01 | Reg Key \Software\ComodoGroup\Comodo BackUp\Users\Backup\Outlook
15.9.2007 at 3:00:01 | Resume started
15.9.2007 at 3:00:01 | Calculating backup size…
15.9.2007 at 3:00:01 | Backup size - 741,009 KB.
15.9.2007 at 3:00:01 | Copy C:\Documents and Settings\janez\My Documents\Outlook data.
15.9.2007 at 3:00:02 | Compared 3 files, 1 folders.
15.9.2007 at 3:00:02 | Copied 0 files.
15.9.2007 at 3:00:02 | Backup “Outlook” completed successfully.

If you need any additional info, let me know.

Thanks and best regards