I noticed that Ovidiu had posted a similar question in April but, since there were no replies, I'm going to present my issue.
Although all appears to be working properly, avast! is cranking out an error message in the avastfileshield.log at irregular intervals. A partial listing of my log reads:
[895-err] Wed Jul 11 14:56:30 2012 - kext_setsockopt: setsockopt failed. Operation not supported [45]
[895-err] Wed Jul 11 15:02:22 2012 - kext_setsockopt: setsockopt failed. Operation not supported [45]
[895-err] Wed Jul 11 15:14:29 2012 - kext_setsockopt: setsockopt failed. Operation not supported [45]
[895-err] Wed Jul 11 15:22:12 2012 - kext_setsockopt: setsockopt failed. Operation not supported [45]
[895-err] Wed Jul 11 15:22:13 2012 - kext_setsockopt: setsockopt failed. Operation not supported [45]
[895-err] Wed Jul 11 15:22:13 2012 - kext_setsockopt: setsockopt failed. Operation not supported [45]
[895-err] Wed Jul 11 15:22:14 2012 - kext_setsockopt: setsockopt failed. Operation not supported [45]
[895-err] Wed Jul 11 16:48:55 2012 - kext_setsockopt: setsockopt failed. Operation not supported [45]
[895-err] Wed Jul 11 16:48:57 2012 - kext_setsockopt: setsockopt failed. Operation not supported [45]
[895-err] Wed Jul 11 16:48:58 2012 - kext_setsockopt: setsockopt failed. Operation not supported [45]
[895-err] Wed Jul 11 16:48:59 2012 - kext_setsockopt: setsockopt failed. Operation not supported [45]
[895-err] Wed Jul 11 16:49:13 2012 - kext_setsockopt: setsockopt failed. Operation not supported [45]
[895-note] Wed Jul 11 17:04:29 2012 - Detected unmount of /Volumes/PC_USB
[Note that this is a truncated but unedited list. There were no intervening messages other than the ones shown.]
I haven't determined any particular action associated with the message. As you can see, it may go an hour or more without occurrence or appear four times in five seconds. Any ideas?