I've a this query in mySQL (MyISAM):

```
SELECT * FROM `links` WHERE `id` IN (SELECT `link` FROM `posts` WHERE `read_time`<'2010-10-16')

```

It seems ok for me, but MySQL hangs up with it.
'links' is a table with 16000 rows and 'posts' has arround 5000 rows.
'id' and 'link' are primary

I've made some tests:

1. Remove all records except a couple in each table. It works
2. Execute inner query (SELECT `link` FROM `posts` WHERE `read_time`<'2010-10-16') first and the execute the outer query (SELECT \* FROM `links` WHERE `id` IN ('1232','1354','3324')). It works
3. Try to upgrade my Ubuntu, but it says that this is the last mySQL version (5.1.37-1ubuntu5.5)

What's happening? I've found a bug? Or am I doing something wrong?