unable to tap multiability cards (land)

First time poster and new user of xmage here. The program is great so far,I'm just having a problem tapping land that has multiple tap abilities(possibly not limited to lands, I just haven't tested other cards yet). After I click on the land to tap it, it prompts me to select what color I want and as soon as I click to select my chosen color the prompt window closes and the land doesn't tap. I've tried clicking on every possible part of the screen while the prompt window is open and still no luck. Has anyone else had this problem? Even if you haven't experienced this issue any ideas on how I could fix this would be appriciated.