I only recently noticed the key command “.” for switching between time and bars+beats. I like it a lot and I use it a lot! The problem is that a lot of times it doesn’t seem to work. I just checked the key commands and the “.” is still applied. I also tried applying a new key command and that doesn’t work either. Anyone have an idea of why the key command would not be working?
Some keycos just work when the relevant window is active. Mixer or project window.
This behaviour is ages old now (since C7, where the window handling was changed but not exclusively improved sadly). Pretty bothering for many users with multiple monitors, I’d really love to see this problem solved in 10 or even better in a maintenance update. Even better better right now 
This seems to be a different issue as it doesn’t matter if I have the arrangement window in focus. The key command simply doesn’t work. Other key commands work fine. Ironically, my studio computer with two monitors (and running 9.0.10 instead of 9.0.30) does not have the issue.
My first elimination would have been what marQs said about window focusing. And I completely agree since C7 KC’s are a mess and it’s going to get worse until the focus/KC issues are finally addressed. Not only multiple monitors, but single monitors with multiple windows open. And I’ll add my rant about many pop-up tool tip names not corresponding with the KC names. IMO a total re-build needs to happen that would include a better search function for KC’s.
Did you try trashing preferences?
You went back to 9.0.10, then did you try 9.0.30 again with the same problem? If so I would send a support ticket to Steinberg.
“a lot of times it doesn’t seem to work.” Intermittent problem. Does that mean half the time it doesn’t work?