I requested some clarification on a blender note and received the following from Prosper that may have answered the problem - at least on future notes:
Dear blue,
Prosper's new lender service agreements state that should the lender take out a Prosper loan and default, Prosper may use the lender funds to offset the defaulted note. This however, is only available when lenders agree to the new lender service agreements. The borrower/lender in question has not agreed to the new lender service agreement. Prosper is therefore not able to reserve his lender funds. This applies to charged-off notes but not discharged notes due to bankruptcy. These notes have had their balance reduced to zero as a result of the discharge. Thank you for using Prosper, please let us know if you have any further questions.
For future reference, your Prosper support case number is xxx.
Sincerely,
Prosper Customer Support