stuck or link issue: is it Video, Pathauto or Tagadelic?

Drupal 5.1
modules: all current as of this date

I'm really stuck on this, and not sure where it is coming from or causing it.

I'm using Video, Pathauto and the Tagadelic modules together.

Everything appears to be fine, except:

When I click a Tag from Tagadelic block, I get the summary page --- all is good

... but when I click on the Node Title Link from there, I get a Page Not Found

does anyone have any suggestions or seeing this too?

thanks