Running WFO QM 18.104.22.168, found users complaining that audio recordings stop at the 15 minute mark. Examining the recordings verses the contact records in QM, I confirmed that the audio recorded is indeed 15 minutes long, while the call duration can be significantly longer.
If you are running 9.0 with Service Release 4, found in Control Panel | Programs and Features in the name column, you can may be able to adjust the CUCM SIP Session Expires Timer to lengthen the available recording duration.
The default is 1800 seconds, meaning CUCM sends a keep-alive to QM at 900 seconds or 15 minutes, and QM responds, but with an invalid codec in the SDP message. The SIP call is dropped at that point and the recording stops.
Supposedly this is fixed in QM 10.0(1).