Wow, this thread is back from the dead. Thread necromancy!
1 year, 8 months, 8 days since last reply. Heck, I've refi'd my house and had another psudo-closing since then.
carmikemom, in the future you might consider starting a new thread instead of posting to an significantly old one.
In response to your situation - it is very common for the debt of ones mortgage to be sold as a financial instrument to another investor. I believe this is common practice, as mortgages - while they have significance meaning to us; truly are just loans with defined terms and are bought and sold as such in the financial industry.
Whether this practice is a good idea in the broader, worldwide economic sense is certainly up for debate, but as the loan holder I believe it has negligible impact. In any mortgage I've heard of the original agreed upon terms are immutable regardless of who holds the debt.
I am confused why the monthly payment would have changed - you should consider calling the company servicing the debt for clarification. Perhaps there have been changes to the way in which insurance and property taxes are escrowed.