The Loan Note Guarantee constitutes an obligation supported by the full faith and credit of the United States and is not contestable except for fraud or misrepresentation (including negligent misrepresentation) of which the lender or holder has actual knowledge, participates in, or condones. A note which provides for the payment of interest on interest shall not be guaranteed and any Loan Note Guarantee or Assignment Guarantee Agreement attached to, or relating to, a note which provides for payment of interest on interest is void. The Loan Note Guarantee will not be enforceable by the lender to the extent any loss is occasioned by violation of usury laws, negligent servicing, or failure to obtain the required security regardless of the time at which the Agency acquires knowledge of the foregoing. Any losses occasioned will not be enforceable by the lender to the extent that loan funds are used for purposes other than those specifically approved by the Agency in its Conditional Commitment for Guarantee. Negligent servicing is defined as the failure to perform those services which a reasonably prudent lender would perform in servicing its own portfolio of loans that are not guaranteed. The term includes not only the concept of a failure to act, but also not acting in a timely manner, acting in a manner contrary to the manner in which a reasonably prudent lender would act up to the time of loan maturity, or until a final loss is paid. The Loan Note Guarantee or Assignment Guarantee Agreement in the hands of a holder shall not cover interest accruing 90 days after the holder has demanded repurchase by the lender, nor shall the Loan Note Guarantee or Assignment Guarantee Agreement in the hands of a holder cover interest accruing 90 days after the lender or Agency has requested the holder to surrender the evidence of debt for repurchase.