iPhone Hot Charging Bug?

I finally got my hands on the iPhone 4 (portuguese article - google translation available) and have been very happy with it.

However, a couple days ago I experienced a very strange event. As I was streaming some live video using the UStream App for the iPhone and my battery was draining fast, I decided to plug it to charge it - while streaming.

Before very long, I start noticing the iPhone 4 getting increasingly hot... and a few moments later I saw the infamous excess temperature warning pop up on screen, making the iPhone enter "safe mode".

Well... it was a really hot day (about 35ºC / 95ºF) and I was streaming video... and charging it...
It was odd... but I quickly dismissed it as a one off event.

Until... yesterday, as I plug it in to charge it as I usually do every night... I once again notice it increasing in temperature... FAST!

I checked to see if I had left any "intensive" App running... but everything was apparently normal.... except for the temperature in the bottom backside and connector area, which was hotter by the minute!

Yes... it could have been a bad/faulty connector - (and keep in mind this was indeed another charger and cable than the one I used days before) - but to rule that out, I simple turned off the iPhone 4 and turned it on again.
And presto... it quickly cooled of to the regular charge cycle... within the acceptable temperature levels... without me even touching the cable/connector (ruling that out.)

I sincerely don't know what's going on here, but today I was surprised to see someone else reporting an iPhone 4 catching fire while charging.

Truth be told, even in my old iPhone 3G, I noticed a similar pattern a couple of times (once waking up to find my iPhone had been burning up the entire night while charging!!!)
This happened just a couple of time over the course of an year... But I'm not very happy to see this odd behavior still happening in a brand new iPhone 4.

If it might be of any help to Apple, to find this bug; the excess temperature doesn't "feel" like the temperature increase cause by CPU use, but more like a battery charging temperature issue.

Hope this is fixable! As I'm now forced to wait a couple of minutes everytime I plug my iPhone 4 to an USB port, to check its temperature and ensure everything is right!