The problem is not limited to dissapeared INVITES -
now thanks to Skype it is possible to know and discuss player status issues - we (players) realize that play status of players is not seen in the same way by different players -
e.g. Players A,B,C,D, wish to play ALT game : A invites and sees B & C as Green but D is Red - D informs us he is green and B & C confirm this but D remains Red as seen by A -
Only way to invite friend D is by manually entering the name of D - then invite is received and play can commence - most annoying and it has caused much animosity among friends when playing CC games where agreed times are not upheld by all players due to this issue.
Last update is the when all this started to happen and it appears that WGT has gone one tweak too far !