Lumia 900 Foursquare and Lync

[phirefly]

Ever since I upgraded to my Lumia 900 my Foursquare live tile no longer updates. Thats not a big deal but it makes me wonder about Lync. My company just enabled external Lync so I never had it on my previous phones but it only works when it is running in the foreground. I enabled push notifications but I don't get any and messages say they are undeliverable unless I have Lync up and visible. Are these just 2 isolated issues or is it something funny with the new version of WP and certain apps? I also use wordfeud quite a bit and it works fine so I know notifications can work.