Problems with new kernel

[Ryan D'Baisse]

Okay, where do I start?  I've tried searching, but I'm not entirely
sure what I'm searching for.  I've found a ton of pages that give
switches to disable certain items, but nothing really explains what
the switches are.  The pages that do explain the switches do not
explain what ramifications they will have.

Here's the problem...

I tried installing FC3 and had to disable ACPI.  Then, I could not get
my wireless NIC functioning.  I found a ton of threads discussing ACPI
and PCMCIA NICs with DriverLoader, so I decided to ditch it and go
back to FC2.  I installed FC2 with the 2.6.5-1.358 kernel and it works
fine (that's what I'm on now).  My first update brought with it kernel
2.6.9-1.6_FC2 which I cannot boot at all.

My questions are simple (I think):

1. What is the best way to tell what is causing the boot to fail?
2. What the heck is so special with with kernel 2.6.5-1.358 that it is
the only one I can boot?

Sorry for more newbie questions.

Thanx,
Ryan