One of our clients used to have a sysadmin with a knack for 192.169/16. Haven't had any problems yet but its bound to happen eventually.
EDIT: I just realized you said 192.169/16, which is definitely not available for private IPs.
A company I worked for, which is basically a group of a dozen acquisitions, uses practically every RFC1918 block which makes things really annoying. 10./8 used by IT, 192.168/16 used by company X acquired in 2004, 172.17/16 used by company Y acquired in 2011. The list of routes the VPN software installed was impressive.
By the way, I use 172.30/16 for my home net. I have personally seen use of 172.16/16 and 172.31/16 before.