last minute strike-offs on tax sales?!

[Mark Mays]

I reside in Houston and have been attending sheriff tax sales on the courthouse steps for a while. I've been doing my research and normally narrow down my potential buys to about 5 properties. It seems time and time again the properties get struck-off the night before or the morning of the auction.

So my basic question how does this "really" happen? People that don't have money for several years all of a sudden get if off the auction list the day before because they mysteriously found money? Or is there some other angle that gets played behind the scenes that I'm not aware of?

Thanks in advance for your response!