Hi, I'm new to the forum and quite new to Linux too
I'm using KDE and my graphics card is ATI Radeon HD 5450.
When I resize a window, the window gets messed up. It either turns black or it shows my desktop background and some artefacts in the window. I think it has something to do with desktop effects. The problem sometimes disappears if I change desktop effects settings but after reboot it's back again.
I didn't have this problem earlier so it probably appeared after some updates.
If I resize my browser's (Chromium or Konqueror) window while running some Java applet, it freezes the applet and I have to refresh the page.
On Firefox I can't run Java at all because the browser crashes every time.