Hello,
 
I have this problem too. I am using HD 3650.
You can edit the shellstyle.dll to solve this problem.
 
1. Open Display Properties >Appearance > Color scheme
    Change Color scheme to other scheme ( No Aero Green/Blue/Black because you are going to edit it)
2. Use Resource Hacker to Open Shellstyle.dll in C:\WINDOWS\Resources\Themes\Inspirat2\Shell\NormalColor (This is Aero Green)
3. Expend UIFILE>1>1033
4. In Resource Hacker menu, View>Find Text
5. Find "<style resid=taskpane>"
6. Under the <style resid=taskpane>, you will see there are three lines which need to change,
    Change from:
 
background: rcbmp(120,6,0,0,0,1,0);
borderthickness: rect(4,4,4,4);
padding: rect(4rp,4rp,0rp,0rp);
http://i143.photobucket.com/albums [...] 20/old.jpg
to  
background: rcbmp(120,5,0,0,0,1,0);
borderthickness: rect(8,8,8,2);
padding: rect(1rp,1rp,1rp,1rp);
 
http://i143.photobucket.com/albums [...] 20/new.jpg
 
7. Save the file and then Compile Script  
8. Change AeroBlack and AeroBlue too.
 
I am sorry my english is bad. Hope you will understand.