Why's my hair growing back on Halaven?

[jml]

Hi Friends~
I don't mean to a look a gift horse in the mouth, but
can someone explain why my hair's growing back while I'm still on Halaven?
The 1st dose of the 1st Cycle knocked my hair right out of my head, leaving behind the greys. But I welcomed them, because if they could withstand the chemo, then I'm glad to have them.
My scans after the first 3 cycles were good, showing good response, not quite NED, but MED.
I've now completed another 3 cycles/9weeks on Halaven and am due for scans on 1/5, so I'm neurotically and looking for any indication that the Halaven is still doing it's job.
Anectodally & based on some of the difficult GI symptoms I was experiencing due to the mets in my colon, I would say that the Halaven is still working, at least holding things stable.
But the return of my hair is confusing me!
I know some folks experience hair growth on taxanes after completing adria/cytoxan, but I never did that combo. I did do 49wks of Taxol/Herceptin during the first year of my diagnosis & treatment, was bald as a bowling ball and remained so until I was NED and didn't grow hair back until I went to solo Herceptin.
I guess I just don't understand the mechnism of action & how can it be that the same chemo that caused hairloss and disease regression initially can still be effectively beating the disease back AND allow hair growth?
Comment, thoughts?

Keep the Faith~
Jessica