Strange issue with HDClone 9.1.3 in backup mode

Hi,
I have a strange issue with the backup mode. I have 2 disks on my PC (running Win7), C: (a SSD) and D: (a HDD). When I perform a D: full backup then differential ones, all seems to work fine, the verification option says the copy is identical to the image. But when I image C:, quite often I get an error message saying the image differs from the source. So I am wondering : is HDClone/W using VSS or an equivalent when performing the image ? It gets stranger when the error doesn't always occur, again in Windows environment.
When I use the boot media, then the full and diff backups are always successful.
Thanks !
I have a strange issue with the backup mode. I have 2 disks on my PC (running Win7), C: (a SSD) and D: (a HDD). When I perform a D: full backup then differential ones, all seems to work fine, the verification option says the copy is identical to the image. But when I image C:, quite often I get an error message saying the image differs from the source. So I am wondering : is HDClone/W using VSS or an equivalent when performing the image ? It gets stranger when the error doesn't always occur, again in Windows environment.
When I use the boot media, then the full and diff backups are always successful.
Thanks !