I have actually had this error for awhile but didn't ask about it since it didn't do this with all skins.  Now though I noticed it with the new release from Stardock called Stardust so I'm wondering if its something on my desktop doing it or if anyone knows what might fix it.
I'm on Vista Home Premium.  I have provided screenshots.  One using Stardust after its been applied and I re-booted the computer, and then another shot with a WB that works fine, iPhonix (which was applied after screenshot taken of Stardust showing poorly).  You see on the Stardust the button is hiding behind the start menu.





Also here is the text from WB system Info.

Thanks

Your computer has a Windows Experience Index base score of 3.6
Your Windows Graphics Experience score is 3.6

WindowBlinds version : WindowBlinds 6.03 (build 75a x86 - Vista Edition)

WindowBlinds is installed correctly on this PC
WindowBlinds appears to be activated on this PC
(Dell SE198WFP(Digital)) 1 is attached to NVIDIA GeForce 8400 GS
(Generic PnP Monitor) 2 is attached to NVIDIA GeForce 8400 GS

Wblind.dll         2008/03/30 11:29:20
Wbsrv.dll         2008/03/31 16:21:03
Wbconfig.exe         2008/03/30 11:29:34
Wbload.exe         2008/03/30 11:27:14
Wbhelp.dll         2007/08/27 12:54:07
Tray.dll              2007/09/12 18:58:21
Wbload.dll              2007/09/12 18:58:28
Screen.exe         2008/03/29 15:09:18