Asterisk Crashes - Junk at the beginning of frame

Hi I am using FreePBX 2.1.3 and Asterisk 1.2. Every few days I get a crash of Asterisk. The last message I get is ‘interface.c :Junk at the beginning of frame 00000000’ I then have to restart asterisk. Has any one seen this message before and what a possible solution may be?

TIA