"not locked" error on UNLOCK tables

[Arne Ludwig]

Hello,

I am trying to optimize the performance of a very simple application that does lots of inserts into a MyISAM table by adding a lock on the table but it doesn't seem to work. The mySQL server is 4.1.10a.

This is what the program looks like:

conn1 = open a connection to server (database A)
conn2 = open a connection to server (database B)

on conn1 select * from some_table;

on conn2 lock tables another_table write;

while rows in some_table:
on conn1 fetch a row;
on conn2 insert into another_table set ...;

on conn2 unlock tables;

Now all the inserts work fine, but the unlock(!) fails with error 1100
"table another_table was not locked with LOCK TABLE".

Is this the intended behaviour? Why? How can I work around the problem?

Thanks,

Arne