From what I've read, you must have the crystal and two caps. Without them requires a different bootloader which specifies to use the internal clock. The standard bootloaders must use an external clock.
I may have it wrong, but I think it's all in that first link you provided in the first thread. It talks about using a different bootloader in order to use the "minimal" setup.
:Be sure to select "ATmega328 on a breadboard (8 MHz internal clock)" when burning the bootloader.
I still haven't tried my Sparkfun chips yet, but it seems that's not the problem since it works in your UNO.
When I got the original UNO chip working on the breadboard, I had the crystall and two caps as specified on the SparkFun site.