Sounds like a security problem.

I can picture you making an enormous effort, beating long odd, getting a regrow and feelin' stoked.

Only to come out one morning to a dejavu.
I'd get my security duck lined up as a high priority.
Then all I can tell you about the regrow is your 600W HPS is too much light for a regrow.
If, you do see any sign of re-leafing, back off on the light.
A couple small CFLs will be plenty for the first sets.
A large rootball supplying just a few leaves is a good thing, but we want her to have incentive to grow more foilage, yah?

And now ya gotta wait for someone who knows more about this.
I'm wondering if a root pruning would help because I do not know.
Your best goto for that, would be Rusty Trichome, but he got banned here.
He's on a few other boards though, google him and ask.

EDIT:
Here's some regrow info:

http://boards.cannabis.com/basic-gro...oof-enjoy.html

GaGrown has some excellent advice here.

Aloha,
Weezard