Acad 2008 seems to display radius dimensions differently for left and right arcs, one appears as 'normal' with the arrow head on the described arc, yet for the other it sticks the arrow head out on a continuation of the radius. 
Would appreciate any tips on how to return to 'normal' settings.
 
 
 
 
 

Not sure if this is the right answer, as i am new to R2008 and having my own problems, but i noticed that the patch (which you can get from here) does modify radii dimension issues.
 
Worth a try as it also corrects alot of other issues as well.
 
All the best

That sounds encouraging, do you mean the patch lives on the forum site?

Hi Cadmonkey
 
If you go to the 'downloads' section and then put a search in for AutoCad 2008, scroll to 'Patches & Updates' and click on the 3rd entry down in the list.
Click on the 'Info' section on the right hand side and have a read through, i'm sure these an entry in there that talks about the radii dimensioning issues.
 
Then on the left hand side is the downloadable file