charging ps3 controller via laptop/tower usb

ok quick question please, i have always charged my ps3 controller via my pc tower usb ports, no problems, i recently got a superslim, and iv tried to charge it through my laptop, however when i do this the controller is loosing its sync to the ps3 and has to be plugged in and re synced, iv never had this with before when charging through the tower!

any ideas?

Ya, charge it a different way that doesn't make it lose sync. 

Get a charging stand. I just put my controller in it every other day or so. Very convenient...

You might have picked up a driver or something on your laptop. When you connect to PC it can sometimes recognizes that you have plugged in a PS3 controller. Windows may have downloaded a driver for it to work.