Carvey problem with Y-axis drive

I have strange problem in my new Carvey.
When I try do homing, table (Y-axis) shakes.
Electrical connection and stepper motor are OK.
It seems that Y motor driving is bad. After swich on carvey everyting is OK for 10-20sec.
But later always the same, table shakes. Firmware is up to date.

Movie with my problem:

Does anybody know where is the problem?

Carvey is not a kit. It should work correctly right out of the box. Call Inventables.