Don't use the 'm-variables'.
They are private vars that are not accessible from 'outside' of the content-object context.
You cannot access them in CMSms 1.9 anymore.
Every content has some base properties (like title, alias, menutext ... the 'm-variables')
These base properties cannot be accessed using the GetPropertyValue() function.
The GetPropertyValue() function is only to get content type related property values.
(like contentblocks, extra fields ... stuff that only belongs to certain content types)
The base properties are defined in a ContentBase object that is extended by all other content types.
For almost each base property there is a public function that will return the value of that property.
Examples:
Title:
Wrong: $content_obj->mName
Right: $content_obj->Name()
Alias:
Wrong: $content_obj->mAlias
Right: $content_obj->Alias()
and so on.
Here is a full documentation of the contentbase object:
http://www.cmsmadesimple.org/apidoc/CMS ... tBase.html