[Serusers] Clearing fr_inv_timer_avp after failure route

Hey All, I have fr_inv_timer_avp pointing to an AVP named inv_timeout which users are allowed to set and everything is working fine except upon call forwarding from a failure route. Here's the situation... - Call comes in for user(a)domain.com - User at domain.com has inv_timeout set to 10s - User at domain.com also has forward on unavailable to a PSTN number - 10s of ringing to the user elapses - The failure route kicks in and pushes the PSTN URI to a new branch - avp_delete("inv_timeout"); is called - avp_write("i:3600", "inv_timeout"); is called - The PSTN number begins to ring - 10s later SER sends a CANCEL to the PSTN gateway How do I properly clear the users preset inv_timeout and reset it to 1 hour for the PSTN destination? Thanks, Evan