I'm using the HC(S)12 version of OSEK, but I'm hoping there's enough parallels between that and HC08 to help you out. Did you install Codewarrior first, then OSEK? Codewarrior needs to be in place first for the OSEK installer to recognize it and adopt its paths and directories. When you ran the OSEK installer, did you choose the Codewarrior integration option? This is necessary because for Codewarrior to work with OSEK, a lot of key OSEK files have to be copied into the Codewarrior directory. You can verify this by searching the Codewarrior directory for an OSEK sub-directory. Finally, OSEK projects don't show up in the project stationary choices. You have to use the New Project wizard, where you'll get prompted to use OSEK in your project. HTH.
---Tom