I spotted two isolated issues where a Googler confirmed a weird bug in Google’s web search & quality classification system. TheJack from Google posted responses in two different Google Webmaster Help threads.

On one he said a site was having issues showing up in Google’s search results due to Google having “misclassified the site as a parked domain.” He added:

I then spotted an additional thread within the same time frame where TheJack, a Google employee, said a similar thing:

He recommends, in some cases, if you are having issues with your rankings, it’s best to post them at Google’s forums.

Forum discussion at Google Webmaster Help.