Park causes phone lockup

[joewilcox]

We have an 48x running software 7.5.15.2. Our receptionist's phone is a 9224 with 2 expanders on it running software version 2.5.10.1. Once in a while when she will place or retrieve a parked call the phone will completely lock up and require a powercycle to fix. The call being parked or retrieved is usually dropped when this happens. It doesn't happen every time (once or twice a week) and there doesn't appear to be a pattern. What can I do to troubleshoot this further?
Current troubleshooting done:
1. Latest software updates
2. look for particular steps done before it locks up which lead us to it being a parking issue
3. tried a different 9224 phone, no change

Any help appreciated.

[theraven40]

I had this issue once in the past and it ended up being a codec issue between the Allworx and a Cisco phone system.