Fresh image will not do incremental

I have a full image:

C_System.tib

and two incrementals:

C_System2.tib
C_System3.tib

The other day my computer got hijacked by some crummy website and a bunch of crap was installed on my computer.

My thought "This is a perfect time to try out my TI backups".

So I used the last incremental (which happened to be the previous night) and re-imaged my system drive (via the bootable TI CD I had made).

Perfect - my system was back up and running in about 15 minutes.

That was two days ago. Today I wanted to make a new incremental.
TI creates a C_System4.tib but its a full image.

C_System1.tib : 9,258,818,560 bytes
C_System2.tib : 497,184,768 bytes
C_System3.tib : 626,855,936 bytes
C_System4.tib : > 9,258,818,560 bytes (dont know the exact size - I deleted it)

Why is this happening? My guess is that somehow when I re-imaged my drive it is significantly different than the previous images. But this does not make a whole lot of sense since I imaged from those images.

Is this behavior normal? Is this what I can expect anytime I image (the inability to keep using my good images for base of incremental)?

Please help.

 

Hi dswigger,
it's normal. If you make a restore no incremental Backup is from this archiv possible.
Dont forget: if you defrag your HD , You cannot make an incremental Backup more too.

 

I understand about defrag but I do NOT understand the other part.

I really want to know why I am unable to continue where I left off - its supposed to be an exact copy is it not? There has to be some answer other than "just wont work"...