Using older kernels with lenny?

[Eric Meijer <eric_no1spam1@xs4all.nl>]

Hi all

I have installed a system with lenny and when the system boots with an 
usb printer connected (HP PSC 1210 all-in one) it hangs.  Also, the 
internet connection does not (seem to) come up.
(I have no direct access to the system now, need to travel physically to 
look at it again).
I want to try another kernel version on this system.  I see that there 
are different  versions of linux-image-2.6.26, numbered 
linux-image-2.6.26-1-etc and linux-image-2.6.26-2-etc.
What is the difference between the two?
Is it possible to run lenny with a 2.6.18 or 2.6.24 kernel from etch?

Thanks in advance,
Eric