Ghost 15 network destination is not available (image backup)

I am using Ghost to do image backups of C: drive to a network share. I have already few full backups and many incremental backups and can make new backups. Unfortunately, Ghost shows their status in Backup History as Unavailable at most times.

 

Interesting that sometimes Ghost switches status of some backups to Available. The availabilty lasts few minutes and then the backups become unavaiabe again.

 

The backup job that I use does full image backup weekly and daily incremental image backup. If I manually run the job when the last backup is shown a available an incremantal backup is created. If the last status backup is shown as unavailable a full backup is created. When the job is run automatically it almost always creates a full backup. The network share disk space is being eaten very fast.

 

I am using Ghost 15.0.1.36526 (SP1) on Windows 7 Ultimate 64 bit (no service pack). Ghost 15 before SP1 had the same problem. I reinstalled Ghost (using Control Panel) but it has not helped.

 

Restarting Norton Ghost service. There are no Norton Ghost errors or warnings in the event log.

 

The network share is hosted on a Samba server. The server provides many other shares and all of them seem to be OK. On the PC I can browse the network share, see the backup folder, create files there (even at time when the backups status is unavailable).

 

Thanks in advance for any help.