Buildings auto clearing? turn on your X-MAS lights to let your neighbors know...

It autoclear my buildings this morning and again this afternoon. I'm leaving a bunch of brown houses near SH so my neighbors will have something to tap. I found out if I don't log on for awhile, my town looks normal with handshakes and ready to collect rent and stuff. On my second log on - short span in a few minutes, it will clear all the stuff except for the one neighbor that had been recently tapped my buildings. I will have clear my town before I log off and hopefully my brown houses will come up for rent when my neighbor is visiting.