Memory Leak

Hello,

RedHat 7.0, Postgres 7.1 (libpq), Intel Cel 433, 64mb, 15g hd.

I am running a test which performs 1000 transactions of 1000 updates of a single column in a single table, or (1
tranaction= 1000 updates) * 
1000.  I have no indecies for any of the columns and the table has 3 columns and 200 records.  I do a VACUUM ANALYZE
afterevery transaction. A 
single transaction takes about 3-6 seconds.

It appears that RAM decreases at about 10 to 100K a second until it is all gone.  Any thoughts on how I can
optimise/configurethe db to 
alleviate this problem?  Any hints on where this leak maybe occurring?

Thanks,
-justin