Thanks, Doze! You’re spot on. I tried what you suggested and discovered the error was caused by these lines (194 - 198) in modbak.module.tpl :
$fh = fopen($modx_backup_dir.$database_filename,'w');
if($dumpfinished)
{
fwrite($fh,$dumpfinished);
and in particular fopen and fwrite. Would I be right in assuming my host disallows these strings in post data as a security measure and if so, is this a common practice?
By copying the module code directly into the database I overcame the problem, but surely there’s a better way of solving this....
Apart from that, ModBak worked a treat for me, backed up, moved and restored a site in minutes. This fonctionality really should be integrated with MODx.
Cheers all!