So I am having the same issue. I have checked to make sure I am on the frequency assigned but I am not getting an IFR release phase in the say it boxes and the controller will not give me a release. They just keep saying...This is Houston center on 134.95 (the channel I was told to call for IFR release on) and to please repeat my request. I get a green text in the window and it reads exactly like the sample phrases in the manual. I cant seem to figure this out. Any have any ideas?