Has anyone experienced their Roomba setting off their burglar alarm?

I've experienced a couple of alarm activations since we started using our Roomba.  We've had it for a couple of I have it running everyday and there have only been two activations.

Googling the subject shows that opinion is divided.  I'm not 100% sure if we have pet-friendly PIRs or not.  We didn't have pets when we had the system installed.  We did end up having my step-daughter's cat stay with us for a few weeks and he didn't trigger the alarm at all.