Only 2 characters available

I just bought GW last night, and installed it this morning. I'm told I should be able to create 4 characters, but am only allowed 2. After creating 2 characters, I can still get to the character creation screen, design the character, and name the character. But it is that create button that is grayed out. I tried "Val Halla" and it said that name was taken. After that, the create button has been totally grayed out. No matter what name I try I cannot get it to be active again. And for the record, ALL my names are totally G rated.

Is there a known reason for this?

That's definitely weird. I assume that you've tried making a new character after restarting the Guild Wars client too.

I think that the only thing left for you to do is to head over to the Guild Wars support page and send them a question from the "ask a question" tab.