I've just compiled and installed my first kernel on the SheevaPlug, and after rebooting I found the following messages in the syslog. I've copied the System.map file from the source root directory (kernel was compiled on the plug, on an external hdd) to /boot, but that doesn't seem to help, it still says it cannot find the map file.
kernel: Inspecting /boot/System.map-18.104.22.168
kernel: Cannot find map file.
kernel: Loaded 30109 symbols from 4 modules.
kernel: Linux version 22.214.171.124 (gcc version 4.3.3 (Ubuntu 4.3.3-5ubuntu4) ) #1 PREEMPT Tue Jan 5 22:04:09 CET 2010