Inbound & Outbound Recording is Different
Recording Inbound calls is accomplished differently than for Outbound calls. With Outbound calls you can decide at the time of placing the call if you want to record the call. But with Inbound calls you must decide when you setup the Inbound phone number if you want inbound calls to that number to be recorded.
Recording Inbound Calls requires the Hosted Voice upgrade (or the Enhanced Inbound add-on). Please see this section for more information.