SunRocket and phone attached to fax machine

I have a Brother Personal Fax machine/phone model 190 that I was hoping to
use along with all the other landline phones in my home with SunRocket. All
my other phones work great (after disconnecting the VZ incoming line at the
outside box) but the Brother 190 just tells me 'Call Pickup' which typically
means an incoming call is coming in (i.e. ringing) and when I do lift up the
receiver I hear just some buzzing, not a dial tone.

Again I was hoping to at least be able to use the handset attached to the
fax as just another phone, and I'd deal with trying to get the fax to
actually fax (both incoming as well as outgoing).

Anyone know what might be wrong/happening?
I know my Brother fax/phone is old but....

Also, does anyone have a fax machine (with a handset) hooked up and in use
with SR that actually does work...at least the phone? If so what
brand/model.

Thanks,
Walter

Walter Cohen