CREATE TEMP TABLE

Hi everybody. I have a problem with my PostgreSQL DBMS.
In serverl log file I periodicly have errors like:

2004-03-24 11:43:18 ERROR:  Relation "tmp_table1" does not exist
2004-03-24 11:43:18 ERROR:  Relation "tmp_table1" does not exist
2004-03-24 11:43:18 ERROR:  Relation 'tmp_table1' already exists
2004-03-24 11:43:18 ERROR:  Relation "tmp_table1" does not exist
2004-03-24 11:43:18 ERROR:  Relation "tmp_table1" does not exist

I figure out that this is connected with query I use in one of the
function:

CREATE TEMP TABLE tmp_table1 AS SELECT bla-bla-bla.

The problem is that when I had no so many users I have rigth now
everything was ok, but now I have quite more users, so this problem
appeared. Function , which use this query, is used all over my web site,
which is base on PostgreSQL.

So anybody have any idea how to correct this or maybe I have to change my
query. Any help would be appreciated.

I'm using PostgreSQL 7.3.4

Thanks a lot.