Windows borders problem

Hi. I am considering purchasing windowblinds6 for vista but the trial version has some issues with my pc.

Always I open the windows firewall dialog, the border looks like this:

And not only in that window. Sometimes other windows fail to draw correctly too.

WindowBlinds version : WindowBlinds 6.3 (build 109 x86 - Vista Edition) - Shareware - 64 bit OS

WindowBlinds is installed correctly on this PC
(Monitor no PnP genérico) 1 is attached to NVIDIA GeForce 8800 GTS 512

Wblind.dll         2008/09/17 10:48:00
Wblind64.dll         2008/09/17 10:48:07
Wbsrv.dll         2008/09/17 08:05:00
Wbconfig.exe         2008/09/17 08:05:57
Wbload.exe         2008/04/26 16:14:14
Wbhelp.dll         2008/04/26 16:14:07
Tray.dll              2008/04/26 16:14:21
Wbload.dll              2008/04/26 16:14:28
Screen.exe         2008/07/22 16:42:31

 

My vista is spanish.  Thanks.