This idea came about within the first week or 2 of owning my MBP while I was doing a lot of research regarding different types of hardware. I don't recall which ones they were at this time (ended up not purchasing either of them and am not going to spend the time it would take to go back looking at all the sites I did at that time to find them), but I found 2 different maufacturers that had specific notes in their FAQ's about connecting their USB devices to the right side port on MBP's. This is just one of the tech support items you kind of file away in your memory in case you find someone having a similar problem. The issue related to not enough power through the right side port due to it sharing power connector with the FW ports. According to my memory, the issue was primarily related to powering their device while simultaneously having a FW device connected, and possibly not having enough to power their USB device adequately. Both of the 2 places I found this item specifically recommended using the left side USB with their device. It has nothing to do with a faulty USB device, but with the inherent design of the power bus on the MBP. Both of these 2 manufacturers were aware of this and provided info. I do not remember finding anything related to their devices frying the bus, only in their device not working due to not enough power.
I found references to Protools and Audio devices, the manufacturers claim that there are timing differences on the right hand USB (i.e they say you could get dropped samples at high sampling rates), no mention at all of power problems nor that it only happens when the FW is in use.
Strangely the users complaining of problems with this hardware online seem equally split about whether the left or right works better (according to the hardware diagrams both are fed from the same chip, the only real difference being the length of the wires.
It is possible that timing issues could be down to poor screening but more likely these devices were designed for FireWire and have been adapted for USB which although theoretically capable of high speeds in practice the "up to 480Mb/s" is under perfect conditions and very rarely achievable.
Anyhow Apple claim full spec for both ports so if if you could prove it wasn't able to supply enough current to meet the spec then you would be able to get it replaced/fixed etc under warranty.
Knowing how simple the Shuffle design is I wouldn't be surprised if under some conditions (i.e if the battery had been completely drained) it could be attempting to draw more than the spec allows but that still shouldn't cause a hardware problem as the spec for USB and FW ports (and other hot-pluggable ports) calls for short circuit and over-current protection.
btw, is this the new Shuffle or the old one, my brother is having problems with his new Shuffle and the front USB port on his PC (which like you I built for him).
Amen-Moses
