LG Vortex switching to Modem Mode? NEED FOR WORK?

I try to plug my LG Vortex into my work PC (Windows XP) and switch the phone to mass storage mode. After a few seconds, and after the Removable Disk Icon (Next to all my other Drives) goes away/comes back repeatedly, the phone switches itself back to modem mode. WTF? I need to get pictures off my phone so I can use them at work, but I can't do this if it won't let me use the phone's SD card. Help please! This is really pissing me off...