solo/unsolo issue help

hey i just upgraded from cubase 6 and issue im having when loading certain(not all) projects up is if i solo a track on project window, than click solo again it mutes that track and all other tracks remain muted rather than unmuting all tracks when i unsolo like it it did in cubase 6. To unmute everything i have to now click on the unmute all solo states button at the top of screen which is super annoying. is there a way to fix this?