Fatal Error when installing NMS

[DaC]

Hey,

I've been trying to install NMS, when I try to FTP upload it, and access the admin panel (just going to /admin) I get the following error:
"Fatal error: Call to undefined function: addimagedir() in .../modules/NMS/NMS.module.php on line 291."

I'm running the standard 1.2.3 version of CMS and I have CGExtensions and CMSMailer installed as required.
I've tried cleaning the cache but that didn't help.

Any help would be appreciated

Thanks

DaC