race condition for drop schema cascade?

I have seen this failure several times, but not consistently, on the 
buildfarm member otter (Debian/MIPS) and possible on others, and am 
wondering if it indicates a possible race condition on DROP SCHEMA CASCADE.
================== pgsql.30167/src/test/regress/regression.diffs ===================*** ./expected/tablespace.out
SatDec 11 13:05:32 2004--- ./results/tablespace.out    Sat Dec 11 14:35:24 2004****************** 35,37 ****--- 35,38
---- NOTICE:  drop cascades to table testschema.foo  -- Should succeed  DROP TABLESPACE testspace;+ ERROR:  tablespace
"testspace"is not empty======================================================================
 

cheers

andrew