dnsmasq fails a few seconds, then get back to normal (debian)

I am running a box with debian 6.0.8, and DNSMasq 2.55 (from Debian repository).

I use it to resolve some local hostnames, and it mostly works fine. but some times, it will fail to answer requests for a few seconds, and then gets back to normal again.

I am just wondering what could cause these "gaps"?

I have not seen anything wrong in syslog or anything.