New, strange error message

All,

I've just started seeing a strange error message in pgadmin3-1.8.2 on a 
FreeBSD-6.3P1 system. I've just upgraded to pg-8.3.1 using ports. In the 
SQL window any query gives me a pop-up saying :

An error has occurred:

Cannot get priority range for scheduling policy3.


If I hit the OK button the query runs fine and displays the result set 
normally. What's going on here? Is this related to 8.3's tightening of 
casting?

thanks,

rl