Is it normal for my iPod 4th Gen (Clickwheel) to get hot while charging?

Hi everyone,

Recently I recieved a prebuilt, flash modded, iPod 4th Gen (Clickwheel) as a gift for my birthday. The iPod runs great and plays music and games just fine. However, I noticed from day one that the iPod seems to get hot while charging, from every form of charging; the computer, wall outlet and battery bank. It gets hottest at the top of the iPod around the screen and after long charging periods, the heat spreads across the device. It has never got burningly hot, yet hotter than what I would think to be normal from a mobile device, can anyone confirm wether this normal or not? Another point of concern is the FireWire to 30 pin adapter that I purchased of eBay, which was bought as a way to charge the iPod from the wall as no 5W USB charger has ever worked on any of my iPods. The problem here is the power adapter seems to make quite a loud whining noise when plugged into any wall outlet regardless if the iPod is plugged in or not. Is this normal for the old FireWire charger as they output much more current than most power adapters?

Any help would be greatly appreciated.

Thanks, Nat.