SUM()ming a view's column

Hello,

I have run into the following problem:

workunit=> select * from v_wutest;
estimate
----------
1650
100
(2 rows)

workunit=> select sum(estimate) from v_wutest;
sum
------
4950
100
(2 rows)

Here, v_wutest is a view which returns two rows. Shouldn't the SUM
aggregate simply add these two values? To me, it looks like a bug.
Isn't it one?

I am using PostgreSQL 7.0.3 here.

-JPL