FileVault couldn’t be enabled for user…: Apple Support Communities
jfucci has the answer. It appears that once you enable FileVault in Lion, you are able to install ESet Cybersecurity and use it normally.
I, too, have ESet Cybersecurity. I tried just running the repair permissions through the Disk Utility, but that did not work. Only after I uninstalled Eset and then ran repair permissions did FileVault finally enable.
via FileVault couldn’t be enabled for user…: Apple Support Communities.

