Odd. Works great for me. I tap the (+) button, then I get the edit screen. I put my task, tap on "when", tap on "no repeats", then I see what I showed on the screen shots, and everything works quick and fast.
I seem to have not caught what phone you are using? Astrid is actually one of the highest rated Task apps in the Market and almost always appears in blogs' regarding "must have apps" or "top apps" for Android, which is why I'm a bit confused as to why its not working fine on you. I configured it to several friend's phones and they love it. Did you move it to SD?
Don't get me wrong here, but it seems difficult to see how an app rated 5 stars by more than 25000 users including me be this buggy on your phone, which is why I am wondering what model you could be using.
Anyway, I think I saw a Producteev app on the market. I should have all the same features as Astrid, since Astrid originated as an Android app built to sync to Producteev.com (before there was an Astrid.com task service), so you may want to check that out.