Hello-
Check out this link :
http://support.microsoft.com/kb/875356
Add this to the exception list (it might be a little different on your PC)
I would go locate the HPScan.exe file location.
C:\Program Files\HP\HP Officejet 4625 series\bin\HPScan.exe (the printer might show up as 4620 series)
After adding the above files and ports to the exception list, please try to scan and check.
I hope this helps.