Well... was it a formatted partition? ;) My guess would be that (since you got errors with wb copying) there is something wrong with your hardware. What can be done is:

Edit s/startup-sequence - remove the >NIL: at the end of the startup command. Boot with no startup-sequence (boot from the morphos partition of course, not the amigaos one!). Type something like: myamigaospartition:c/execute s:startup-sequence. This should be a bit more verbose and will probably give you enough information to figure out what's wrong.