HCF driver downloads for Fedora Core 3 i686 kernels

At the start of the month I sent an email to this list, which was kindly 
answered by Jonathan of Linuxant.

In light of his answer, I afterwards downloaded and installed Fedora Core 3 
(kernel version 2.6.9-1.667).

I then found the page at the Linuxant website whose title is the same as 
the subject line of this email. The last four downloads which that page 
listed related to my kernel version.

Given the note on the page about potential problems with the default stack 
size in original FC3 kernels, I tried first to install the version 
described as 2.6.9-1.667.stk16. However, it would not install. I then tried 
the version described as 2.6.9-1.667 and it did install. I have since used 
it and it works.

I would naturally like to switch to the faster version of the drivers, but, 
before I do, I would be grateful for the answers to a few questions, just 
to be sure I'm going about this the right way.

Am I at real risk of some problem arising due to the stack size issue? If 
so, what do I need to do to get installed the first version I tried to 
install, the stk16 one, instead of the version I presently have installed?

On a related issue (or, at least, that's how it seems to me in my 
ignorance), will my drivers cease to work if I install the upgrades to the 
kernel which are now available to be downloaded from Fedora and which it is 
suggested by them I should install?

Thank you for your assistance.