I had nothing but trouble w/ Ubuntu when trying to use anything non-Canonical tested. I suggest using something like Archlinux where you're not forced to stick with buggy software for a 6 month cycle.
And I've been really, really impressed with the latest Thunderbird/Lightning releases (14-15). Haven't had any problems at all, like I had with the older releases from several years ago. I used to be a Mail guy, but Thunderbird blows it out of the water these days.
I know that many of these are trivial complaints and that all of these things can be fixed. I no longer want to have to do this however. In my teens I loved tinkering with the linux desktop, designing 'awesome' Enlightenment themes and enjoyed tracking down and fixing these little problems. Now in my 30s I really just want the OS to get out of the way and let me code. OSX does this well, linux really does not. I say this with a fair bit of sadness as there are many things that I like about linux a great deal - the cli, the excellent package management, the ethos behind the OS and the open source community.