No ad serving issues of which I am aware, misterjonez, and I keep my ear pretty close to the ground. I am assuming that you mean your ads stopped showing, as opposed to all ads - is that correct?
In order to troubleshoot the issue, I am curious to know on what evidence your are basing this - especially since you seem to have pinpointed a particular period during which they were not running.
Is this based on the evidence of your account statistics? Or is it perhaps based on the observations of a friend or colleague who looked for your ads but did not see them? (I ask, since you mention that you did not notice it yourself at the time.)
My best guess is that you might be relying on observation from a friend - and they might not be seeing your ad all the time since searching for your ad multiple times could change the position in which they see your ad on the actual Google search result page.
Or, it could be something as straightforward as a daily budget that is so low that the ads can only show for a portion of the day - even though the system will try to space out delivery over the entire 24 hour day.
In any case, here are some troublshooting resources which will hopefully assist you in getting to the bottom of things:
* Why can't I see my ad?
* Ads Diagnostic Tool
<edit> Added several missing words! </edit>
[edited by: AdWordsAdvisor at 11:35 pm (utc) on Nov. 12, 2008]