Most of the DVD's in my collection plays well on any version of xine-lib, but I found at least one which doesn't like the 1.1.9* version: Playing the DVD with xine shows the language selection screen, the "forbidden to copy etc." message, and then it just quits (Tim Burton's "Sleepy Hollow", region 2, in case someone wants to test it). The mentioned DVD plays without hitch on xine-lib-1.1.8, also with mplayer or vlc. Some problems with DVD navigation, maybe?
emerge -pv xine-lib? emerge --info output? Thanks.
(Sigh) All this up'n'down'n'upgrading of xine-lib must have (temporarily) messed up my system. The problem was real two days ago, but now I'm unable to reproduce the problem with ANY version of xine-lib... so you can write this bugreport off as invalid. Sorry about the noise.