When the kernel first loads it needs to have all of the modules available which are needed to access your / partition. If it can access / then it can load any other modules as needed from /lib/modules/2.4.22.
There are two ways to make sure that the necessary modules are available. The first is to make every essential module y in xconfig ( and throw out initrd).
The second way is to use initrd. SuSE has to provide every module that anyone might need in their kernel. If SuSE made them all y then the kernel would be way too big. So SuSE makes all of these modules m and then builds an initrd at install time which loads the necessary modules. Since your kernel compile is different than SuSE's, their initrd will probably not work with your new kernel. You have to build your own initrd control file with the modules to load (its name escapes me, see man initrd).
Since you know exactly what hardware you are using then initrd is an unnecessary complication. I suggest that you not build an initrd. Take initrd out of grub for your new kernel, but not the old. Then in xconfig set everything needed to access / to y. You may also have to make framebuffers, video modules, and keyboard modules y also.
Be prepared. Create a LifeBoat CD.