I used the below scripts to test with both 4.66 and 4.67. The Call command seems to call the the second script fine with both. I was not able to reproduce the error you are getting. Are you certain the error is not being generated by the Called script, as the call will get an error returned from the second script.

Call.kix
 Code:
Call "\\server\share\userdata$\user\call2.kix"

? @Error
? @SError
get $
Call2.kix
 Code:
$nul = messagebox(@Kix + @CRLF + @ScriptDir, "test", 0)

Exit 0