How long since you tried to access the radio side of iPlayer? It no longer appears to work for pre-1.03.06 standard firmware, and my boxes lock up the same as you have noted, but for less time (variable).I haven't had any issues with iPlayer and have only recently updated my custom firmware (see signature) so wondered if it was a coincidence.
You can update your 1.02.32/2.20 to 1.03.06/2.21 in one hit, see Wiki HERE (click). 1.03.11/2.21 is also available, but not currently listed on the Wiki. See notes in Things Every... (click) section 1.Which is the newest version of the official software I can update to?