On RHEL 6.5 (using samba 3.6.9-167) it seems to recognize 'allow insecure wide links' as a valid parameter but ignore it. When it is set to yes the log file still shows the error that both 'unix extensions' and 'wide links' are set and therefore 'wide links' is disabled.
Another issue if anyone has seen- when we updated our Macs to 10.9 (which uses SMB2 now) we started to have problems with matlab reading and writing files from our RHEL 6.5(ext4) servers. matlab would report it's own errors from the 'load' and 'save' commands such as unable to read or file may be corrupt.
We found we could remedy this by not defining 'unix extensions = no'. This seems peculiar.