Two things, you will need to use the specific USB cable provided with your Bionic and you need to download and install the USB and PC drivers from the Motorola site. The USB cable that came with your phone includes a microchip specific to the bionic. Without it, ot using another USB cable, you are only able to charge your phone. Once you have this connected, download the USB and PC driver from
http://www.motorola.com/staticfiles...al_Drivers/MotoHelper_2.1.32_Driver_5.4.0.exe In case this location changes, you can search Motorola phones on google, select Verizon as the carrier and a graphic of the Bionic should appear. On that page, there should be a link to the current driver. RUn the install with the phone connected and it should take gcare of the rest.
The cable drove me nuts for months because I assumed my old ECOMOTO cables and other 3 parties would work like on my Droid, but the cable is slightly different on the Bionic and has a VCast sticker as in addition to the ECOMOTO sticker.
Good luck