This article seems to have the fix:
Upgrade to Ubuntu Gutsy – emvs and udevd 100% cpu usage – aka udevd going nuts
One typo I noticed: He refers to /etc/init.d/udevd instead of /etc/init.d/udev.
The corrected steps:
# apt-get remove evms
# /etc/init.d/udev stop
# /etc/init.d/udev start