When looking at it back home, the tubular glue had let loose and I could take the tire off without pulling hard.
Since this is my first tubular wheel set I have no experience how it should behave. So is it normal that tubular glue can let loose after approx 500 miles? (Last 300 of them where in wet condition. Nice weather in the Netherlands this time of year

Front wheel is still perfectly glued to the wheel.
Rims: Planet X Carbon Tubulars
Tires: Schwalbe racing Ralph
Glue: Continental Tubular Carbin Cement
Or could it be that I didn't use enough glue on the rear wheel?
Any suggestions?