Hi Kostbo,
Welcome to Microsoft Answers!
As this is by design of the Windows 7 Operating system, we cannot disable the Auto arrange.
The change in Windows 7 is by design however, if this is something you would like this feature reinstated, please submit your suggestion to:
http://mymfe.microsoft.com/Windows%207/Feedback.aspx?formID=195
Regards,
Divya R – Microsoft Support.
Visit our Microsoft Answers Feedback Forum and let us know what you think.