Меню and icons don't display on Kubuntu

Since few days (maybe since mid-ноябрь 2015) my KDE display шоу strange behaviours. With some меню, the статьи don't шоу, I хан only read them if I hover the мышь over them. The characters пахал very ugly and bold. But this occurs only with меню like the system меню or some меню like those in Konsole/Kate. With other applications like Firefox or NetBeans there seems to be не problem.

гm currently running on Kubuntu 12.04.5 LTS.

The kernel is 3.2.0-61 generic on в x86-64 (Quad core I7).

KDE версия is 4.8.5

My видео setup is в GeForce GTS 450 with Nvidia драйвер 304.131.

Notice that I apply the updates эксперт soon эксперт they пахал available.

I would like to know what happens because it is very anoying. I tried to были the .kde folder but nothing changed... I don't suspect my видео board because the problem occurs only with some меню. I rather suspect KDE...??????

Do you have an разрабатывает to solve my problem?

Thanks!

Доминик