Problems with Kubuntu and Nvidia

[Alessandro]

Hi all,
I have a Dell notebook with a Nvidia GeForce FX Go5200/AGP/SSE2 with the 
latest driver installed, (NVIDIA 1.0.1.7174). The first time when I have 
installed the Hoary 5.04, some days ago, all was ok. Then I have 
installed KDE with the Synaptic Package Manager..... first problem:

both in the gnome desktop menu and in the kubuntu desktop menu there is 
a mixture of application of gnome and kubuntu together.

Anyway the fonts and icons dimension were right both for gnome and kubuntu.

Whene I have installed the Nvidia drivers all was better, for a 
graphical point of view, but in kubuntu the dimensions of fonts and 
icons were and are still totally incorrect and varying depending on the 
application.
What I have to do?
There is the possibility to set the DPI in kubuntu, like in gnome?

Thak you

Alessandro