My question involves collection proceedings in the State of: California.

This involves a debt of 9,000 dollars on a citibank account, being collected in by Phillips and Cohen associates against my mother. (California is a community property state so the debt transferred to her).
Mother has had three strokes and has verbal aphasia so she is incapable of handling her own affairs and I have power of attorney for both medical and financial purposes. The House was transferred to her ownership (it is held in joint between her and dad) and now is held with her as a life tenant and me as the remainderman.

Phillips and Cohen demands 8000 dollars, however neither the estate, nor the current funds available to mom could cover that. Her assets include 1200 dollars in a checking account, a total of 1500 a month (1200 SS, 300 pension), and a house currently encumbered by a total of 120,000 in mortgage and line of credit debt. The house was origianally valued at 296,000 but that was at the height of the mortgage craze and I believe it was likely radically over valued.

Currently, in phone calls, Phillips and Cohen has threatened to advise their clients, citibank to seek to reopen probate. Can they do that? Can they force the house back into a probate sale? Dad passed away two years ago, in november of 2006.
This is causing me a great deal of fear, because I had to quit my job to watch mom, we have no savings, and if this happens, we are to put it bluntly, homeless with no hope of recovery.