Lexmark x4550 wireless scanning

I have a Lemark x4550 wirelessly connected to my WindowsXP desktop
computer. It prints fine however I can't get it to scan. Using the control
panel on the printer it asks me to select the computer to which I want to
scan, I choose the computer and it starts "Downloading Application List".
This usually results in an error stating it "Cannot retrieve application
list". However sometimes it will give me a list of applications and if I
select one of these and try and scan an error screen comes up stating the
scan failed. There's also no scan icon in the Lexmark Imaging Studio. Any
suggestions.