The new Ubuntu Hardy Heron release broke suspend / resume on my hp compaq nc6320. The bug is reported on https://bugs.launchpad.net/ubuntu/+source/linux/+bug/219657.
For me, however this was the a good excuse to try something new. So I'm running Mandriva Spring 2008.1, and it seems to be a really good release. If you think Ubuntu is well polished (I used to think so,) then think again. Mandriva just works with my laptop too, it makes KDE shine (I used to use KDE before Ubuntu,) and after a year of brown it is really refreshing to have a blue default theme.
What I miss most is sudo(!). Another thing I found out tonight was that there seems to be no bittorrent client installed by default.
