computer recognizes m2450 MSC but not Autodect

My computer recognizes the m240 in msc mode, (both Windows Media and windows Explorer) when in MSC mode, but not in Auto Dectect.  Firmware is 3.2.8, connecting to Windows XP SP3 Home Edition.  I had no problem connecting with my computer at work

Do you have WMP 10 or higher? MP3 players set to operate in MTP mode need WMP 10 or higher to be supported in XP.