I have got plenty to do at the moment. So please excuse the lack of updates. The pipeline is quite full though ;-).
So, just one short thing I found out:
If you experience a strange slow down of KMail/Kontact 4.4.10 after a KDE upgrade in gentoo, reemerge kdepim related packages.
If you use eix you can easily find these packages by typing eix -I kdepim . I do not know if all packages are related but it does not hurt to rebuild them all after a kde update.
You can do this with one command like this:
emerge -1va `eix kdepim -I –only-names`
After that KMail/kontact worked again as expected.