need help w/ high alt IFR flight plans

[AceChaplan]

I've been trying to fly from Kelowna to Victoria at 31000 ft and even though my altimeter is set to the ATIS and it reads 31000 the ATC keeps telling me to expidite my climb to FL310 . Is this a bug or do I have to set my Altimeter to a different pressure setting above a certain altitude? I couldn't find any reference to this in the manuals. Any help would be appreciated!

[wsieffert]

29.92 above 18000ft on ascent, change back to local setting on descent.

[AceChaplan]

thanks!