Arch Linux

There is a bug in Pacman with handling updates to packages that was installed as dependencies for other packages.
When _updating_ such package with pacman -S pkgname Pacman marks it as "explicitly installed". This is wrong!
When updating the same package with pacman -Su it remains marked as "installed as a dependency for another package" which is correct.

Example (some lines deleted for better readability):

# pacman -Su
Targets: kernel26-2.6.17.6-1 libglade-2.6.0-1 libxml2-2.6.26-1 xine-lib-1.1.2-1
Total Package Size: 23.5 MB
Proceed with upgrade? [Y/n] n

# pacman -Qi xine-lib
...
Reason: : installed as a dependency for another package
...
Required By : gimageview gxine xfmedia
...

# pacman -S xine-lib
...
upgrading xine-lib... done.

# pacman -Qi xine-lib
...
Reason: : explicitly installed
...

And now when using pacman -Su, this time for other packages like xine-lib (as we cannot upgrade xine-lib with -Su now):

# pacman -Su --ignore kernel26
:: kernel26-2.6.17.4-2: ignoring package upgrade (2.6.17.6-1)
:: Above packages will be skipped. To manually upgrade use 'pacman -S <pkg>'
Targets: libglade-2.6.0-1 libxml2-2.6.26-1
...
upgrading libglade... done.
upgrading libxml2... done.

# pacman -Qi libxml2
...
Reason: : installed as a dependency for another package
...

See? It differs! This _is_ a bug!