Same subject, different question: FW/USB2 cables

Hey!
As I may be about to close a deal (selling my 3G 20GB iPod) a new question arises:
The user to whom I'm selling my iPod is a Windows user. I'm not sure yet, but he likely doesn't have a FW port in his PC, so I was wondering, if I give him the USB 2.0 cable included with my future 4G iPod (as I have a Mac and have no use for that cable anyway), will it work with his 3G one, and its dock??
I'm just asking this because, apparently, a 4G iPod is incompatible with a 3G dock, even though it's possible to plug it in... 'course, I'm just speculating; this doesn't make much sense, as it would mean that all the third party accessories which use the dock connector should become incompatible too.
But anyway, I was just wondering if anyone tried that already...
Thanks!

I think that the old dock will work - just won't 'fit' perfectly. This is because apple made it like a billionth of an inch thinner or something. I'm pretty sure that it will work - I used a 3rd generation firewire thingie on my 4th generation ipod - no problems at all.

I'm not really sure, but I think the cable delivered with the 4g iPod has both connectors, USB and Firewire. It's not 2 separated cables...
Anyway, yes, the 4g iPod has the same dock connector than the 3g, the difference being that the 4g's battery can be charged through USB (3g cannot).

But the guy who's buying your iPod should be sure to have USB2.0...because even if the iPod works fine with USB1.1 it's so unbearable slow...

The 4g should fit in the 3g's dock, as it's just about 1 or 2mm thinner, allthough it won't be very stable in it, and most of it's weight will reside on the connector, breaking it with time...I never tried it though, so this is NOT a 100% statement ;-)