I have 2 answers (of course may be no one right :lol:)...
1)
YAST resolves automatically the missing dependences, while the command-line tool you used does not.
If, when you installed that RPM, yast downloaded other RPMs (or searched them in the installation CD/DVD/path) then probably this is the right answer.
2)
May be you falled in one the bugs of the new package managing system of suse.
If you go the "Most annoying bugs" section of the OpenSuse page:
http://en.opensuse.org/Bugs:Most_Annoying_Bugsyou'll see that 3 of them are related to it (and this page shows only the most important bugs).
It seems that the change to RedCarped brought a lot of troubles together with the new functionalities!
I hope they solve all that bugs rapidly...