Samsung devices has internal storage mounted as SD Card and the micro SD card is mounted as an External SD Card. Your backup is stored in tablet's internal memory in the //droidbackupdir/<RANDOM NUMBER> directory. This situation is caused by Samsung's way of mounting memory cards, e.g. backup is saved to micro SD on my HTC device.
I purchased a Samsung Galaxy tab2 10.1 ( UK version).
Having used AVG for many years on my PC and never had a virus I thought it the best choice for the new tablet.
I downloaded it and it worked as expected until I tried to back up my new games apps to micro SD card using the AVG option.
It said it had completed backup, but there was nothing on the card and no SD card memory used. I noticed however that the main memory on the tablet had reduced by the amount of the expected backup.
Thinking I had done something wrong ( as a novice ), I tried the backup procedure again. Same thing happened and my main memory has reduced again by 290Mb.
I have now lost 600 Mb of main memory and have no idea where these "backups" are on the tablet or how to get rid of them, as clearly they are of no use unless on the SD card.
Would appreciate any advice on this.