There have been several reports lately of the DSP hanging on DM81XX and C6A81XX devices. Sometimes it's a SysLink sample that doesn't run, a SYS/BIOS-only app who's timeouts are taking too long/short, or an existing app that worked fine, but fails when updating to a new EZSDK, Linux, or SYS/BIOS release. In many of these instances, the issue is the result of a dmtimer misconfiguration - in the DSP-side SYS/BIOS config script.
There is a nice article summarizing the DM Timer issue (and fix!) that we just posted to the TI Wiki. I just wanted to give it a little more attention in case you get bit by it, too.