Uptime check false positives

I'm getting reports of downtime during approximately hour-long periods, but my stats show perfectly normal traffic during the same periods. I use a host that is famous for reporting downtime to us that we didn't even detect and then giving us small refunds and large apologies. So I'm pretty sure what I'm seeing with the uptime checker is false positives.

This isn't really a complaint; I just thought I'd mention it so you can look into it if you want to improve the feature. My username is meronoid, so feel free to email me if you want more information.