act_wiz.c, function do_vsearch. The following check needs to be fixed:
if( argi sysdata.maxvnum )
send_to_char( "Vnum out of range.\r\n", ch);
The && there needs to be a || otherwise the command will always drop through and be processed regardless of the argument given to it. This bug affects all versions of the AFKMud codebase, as well as stock distributions of Smaug 1.02a and 1.4a.