Missing depentencies during the installation

[Vinny Onelli]

Hello,
I installed F15 first on laptop, I had rough time with gnome3, after
restore all file it worked some what decent, with some of this forum
help. I then decided to upgrade the desktop Dell Dimension 8300, from
F14 to F15. Apparently that was not a thing to do, F14 was working
great. After clean installation I fallow all the add on installation
that I had done on the laptop but I could not get the same thing, like
icons on the screen similar to gnome 2, the email I can receive but I
can't send, same setting of the working laptop. I then remember that
during the installation the message came on for missing dependencies, I
choose to continue, I thought, that may have been the problem.
I try to install it again this time I choose "customize later"
it still came up with the same message. I thought here is the time to go
back to F14 so I started my old F14 installation disk, and again leave
the selection to customize later I got the same message missing
dependencies, this disk I used before in the very same computer.
Am I to thing that is some thing wrong with computer?
Any help is greatly appreciated. Vinny