way to prevent queries from waiting for table level lock
===

We've encountered a problem after moving the database of our customer to an extra server. This should have had positive effects on the site's performance, but there is a problem with table locking in MyISAM. (I've heard of using InnoDB instead of MyISAM, but we cannot change the engine in the near future).<br />
We could spot it to an update-query which is performed when a moderator activates a comment on the articlesite. This is the process:

 - update-query is processed  `SET status = 1 WHERE id = 5` (index is set)
 - the cached files of the page are deleted

  
At this point the whole page becomes slow. The database itself is busy for minutes. I fetched the processlist a few times and saw about 60 entries of different select-queries, which were all on the state **waiting for table level lock**. <br /><br />
1. I don't unterstand why this update on the table `article_comments` can affect select-statements for table `article` to wait for table level lock. In processlist almost all waiting queries were from this table. I've read about the fact that updates/inserts are preferred to selects and that this can cause such problems, but the articles-table itself isn't updated when comments become activated, so the selects shouldn't wait. Did I missunterstand that?
<br />
2. Is there something besides changing to InnoDB to prevent this behaviour or at least to get a better balance? I'm very irritated about the fact that this problem did not appear before moving the database to the new server. I guess there is some misconfiguration but I don't know how to identify.