MySQL Performance - Option setting

I set OPTION=3 in my connection string as recommended by MySQL
(http://dev.mysql.com/doc/refman/5.0/en/myodbc-configuration -connection-parameters.html)
for a VB application.

OPTION=3 is Don't Optimised Column Width (1) and Return Matching Rows (2).

I found this to be very slow on a database with just 27,000 records. It took
approx. 12 seconds to read 27,000 records.

When I change the OPTION to 8 (Allow Big Results), it took just 3 seconds to
read 27,000 records. BUT now my application cannot update records anymore
and getting random errors on transactions.

I try setting OPTION=11 (all 3 options added together) and the speed went
back to being slow.

Can someone please help?

Tks