Conflict with SoundMAX headphone detection?

I've just upgraded from Comodo 2.x to CIS 3.5.57173.439. When I plug my headphones into the front jack on my system, the SoundMAX control panel detects them and opens its usual popup. I confirm by clicking Ok (twice... it's badly designed). Then the computer locks up, and I have to do a hard reset.

I've made no other changes to the configuration. In fact, I was using the headphones a couple of hours ago, and they worked fine. Did the Comodo upgrade, and bam, headphones are killed.

I fully uninstalled Comodo 2.x before installing 3.x. I installed 3.x in "Firewall Only" mode. Firewall was in Custom mode; Defense+ was Disabled. I've tried setting both "Training" mode. No help. Same result every time: plug in headphones, click Ok, Ok, and the system locks up. The configuration is ASUS P5Q-E motherboard, Intel Core 2 Duo CPU, WinXP Pro SP2. I've been using the system for weeks, running Far Cry 2, Fallout 3, Office 2003, Adobe CS4... all with absolutely no problems.

Before I go any further, does anyone have any suggestions on things I might try to resolve this issue, or narrow it down? Otherwise, I'll be filing a full bug report and/or reverting to Comodo 2.x. Thanks!