Not to hijack the thread, but I seem to have a similar issue. I am told I am in the superadmin group, however I do not have any access whatsoever. I have tried using both the settings/users.txt and the adduser command, however, it does not work either way.
I first added myself to users.txt according to the gmod wiki. Upon connecting I was greeted with the welcome you're in our super-admin group message. However, when I tried to access a command, any at all, I'd get:
"You do not have access to this command, Sleepyhead87."
I then rampaged the forums, and came upon this thread. Upon reading it, I then blanked out my settings/users.txt and went into the console and used the command : "ulx adduser Sleepyhead87 superadmin 1"
This is what I got:
"] ulx menu
You do not have access to this command, Sleepyhead87.
[UCL] Access set.
(ADMIN) (Console) added user Sleepyhead87 to group "superadmin" with immunity
] ulx menu
You do not have access to this command, Sleepyhead87."
As you can see, I first tried ulx menu in my client console. Access denied.
I then went into the server console and added myself, then attempted the command once more. Access denied.
I am using the svn version, atm, however I have also tried the "stable build" with a fresh install (that means deleting my entire gmod folder on the server. I have a slight headache from this as I cannot figure out why it does this.