Possible error in mysql query optimizer ?

[Matthias Horbank]

We have a complex statement created from a web application which does
not work correctly. During analysis, we could reduce this statement to
the following:

SELECT * FROM table WHERE
((row1>=0 AND row1<=2 AND 1) OR 0) AND row2=1;

"row2=1" is not being computed, we also get results with row2<>1;
When we swap the values of our last "AND" like:

SELECT * FROM table WHERE
row2=1 AND ((row1>=0 AND row1<=2 AND 1) OR 0);

everything works fine, the same when the second OR parameter is "1"
like:

SELECT * FROM table WHERE
((row1>=0 AND row1<=2 AND 1) OR 1) AND row2=1;

Please, don't ask about the strange "... AND 1) OR 1)...", in the
original statement it is not a "1" or "0" but more comparisons, which
in this case evaluate to "1" and "0".

Is there something we do not see or is something wrong with the query
optimizer of mysql? We are using mySQL 4.0.21-nt.

Regards,
Matthias.