I work in Linux Fedora 19 - KDE: the PC is a Dell OptiPlex 7010, with an Intel(R) Core(TM) i7-3770 CPU @ 3.40GHz and an external graphics card (VGA compatible controller: Advanced Micro Devices, Inc. [AMD/ATI] Turks PRO [Radeon HD 7570]. So I have two graphics outputs, one from the motherboard and one from the Radeon.
I added a 2nd monitor, and everything works perfectly except two applications (so far): Okular and Mathematica.
Both of them use the a cursor shaped as a vertical white hand - unfortunately I dont know from which toolkit it comes from... anyway in both cases now the transparency fails, and the white hand is surrounded by what is behind the application (or I could say that it is too much transparent ;-)
I tried disabling any graphics effect I could, without success.