ssi_recentTopics time limit?

[rotinhellorg]

I am using ssi_recentTopics to show the last five headlines from a one of the boards on the front page of my site.  Everything was working fine and then it stopped showing the full five posts from that board.  So I went through the SSI to try and and find what was causing it and I found this:

WHERE t.ID [nofollow]_LAST_MSG >= " . ($modSettings['maxMsgID'] - 35 * min($num_recent, 5))

I raised the 35 and that fixed the problem.  But I was wondering if there was a better way of doing this.  Any ideas?  Basically, I want the recentTopics to show 5 headlines whether they were posted a day before or three weeks before.