Migration assistant doesn't see time machine backup

I am trying to reinstall clean Snow Leopard on my iMac. I made a partition on my iMac internal HD(on the same physical drive as a system) for Time machine and ran backup.
After that I started up with Snow Leopard DVD, used Disk utility to clean old system partition and installed Snow Leopard.
But when I run Mingration assistant, it doesn't see Time Machine disk to restore. I see TM partitioning in finder and it's look OK, but migration assistant doesn't recognize it.
How I could force migration assitant to recognize backup? Or how I could migrate my setting from this backup?

 

I used TM only to transfer setting. It provides an option to create backup on th same physical drive. But Migration Assistant doesn't recognize it. I have looked through MRoogle, but haven't found solution how to force MA recognize this backup. I see only one solution - to crate account manualy and after that restore user folders through Time Machine