The problem could be the location of the admin.dat or .cfg files you are editing, some of the specific code in the command block in admin.dat, some of the specific code within the .cfg file...
I haven't helped you at all, partly cause I've only reiterated what you already know. Without having more specifics, I can only say "something is wrong" which doesn't help.
Lets start with this, what are the contents of the .cfg file and where is it located? No, don't say "with admin.dat". I want to know the full path, such as C:/Documents and Settings..."

and copy/paste the contents of the cfg file. Hell, while you're at it copy/paste the command block, It could be a typo there too.
use the code tag, which is [ code ] and [ / code ] (without the spaces) so your code isn't mangled by phpbb when posting the contents of config files..
edit: !readconfig is just that, it does nothing more. When you do !help do your commands show up? (assuming the command block has the desc set for the command that is.)