PC reboot before proceed task sequence

Hello

I`m using my MDT to install win7 and it works fine, but now i add some commands to FirstLogonCommand and it`s stop working at all!

Now it`s boot, i can choose boot image in WDS, it`s loading to Microsoft Solution Accelerators screen and just reboot.

What could be wrong?

i`m trying to completely regenerate boot image, restart WDS server, but any of my 3 boot images from diffrent deployment shares works this way.

By the way, MDT 2012, Windows 2008 R2 as host.