Tom, without meaning to sound patronising, there are different types of agnosticism. All of them surrounding a concept of a deity, or the knowledge thereof of a deity. Both including the term "deity", even if the latter is simply the knowledge of.
You were right when you said that was the "basics" to agnosticism.
Edit: Wait a second, we're both arguing the same point? LMAO. I think that means you misunderstood my initial point of not being labelled agnostic.
I'll try and say it basic cos my mind goes ahead of me at times.
If we take the definition of agnostic as being "An agnostic believes that the nature of God and/or supernatural are unknown and unknowable by human beings, if they exist at all" - which we've both agreed with. Then the reason I do not fall under that, is because in order to have knowledge (and lack thereof), you have to accept the concept of it.