3
One other person has reported a similar error.
I just had to do a fresh install of XOOPS 2.0.7 and No-Ah 0.8.7RC version myself and although I didn't get the same error, I did find some bugs which might cause that.
The fix is now in the CVS. The problem was actually related to the required core extensions. So make sure you've also downloaded and copied them into your XOOPS class folder.
hth