strange behaviour (bug)

Hi,

I experience a strange error with 7.0.2. I cannot get any results with
certain queries. For example, a foo table is defined with a few columns,
it has a 

id_string varchar(100) 

column, too. I filling this table, it contains e.g. a row with
'something' in the column id_string. I give the next query:

> select * from foo where id_string = 'something';

I get no result.

> select * from foo where id_string like '%something';

I get the row. Strange. Then, if I try to check the result:

> select substr(id_string,1,1) from foo where id_string like '%something';

now I will get 's' as expected... Dumping the database out and bringing it
back the problem doesn't appear anymore... for a while... I cannot give
an exact report, but usually this bug occurs when I stop the database
and I start it again.

Did anybody experience such a behaviour?

TIA, Zoltan
                        Kov\'acs, Zolt\'an                        kovacsz@pc10.radnoti-szeged.sulinet.hu
       http://www.math.u-szeged.hu/~kovzol                        ftp://pc10.radnoti-szeged.sulinet.hu/home/kovacsz