So far, I’ve had not had tons of luck with my Moto RAZR V3xx. However, I did strike upon one piece of gratuitous fortune. I purchased the 1 GB micro SD card for my phone. After inserting it, I picked it as the default location (Menu->Settings->Phone Status->Download Location). Finally, I could use the card as a USB hard disk by setting the phone (Main Menu->Settings->Connection->USB Settings) to (the only option I have here is “Default Connection”) to “Memory Card”. Then using a standard USB cable, I can connect to it effortless.
I have had no success with Moto4Lin or KMobilePhone to connect via the USB port to use the phone for PPP services.