An .image with the HydraVM-sig.8 package loaded does not startUp on a  
non-Hydra VM.

One problem is that Hydra's #startUp methods do not check for #isHydra and  
so they stumble into a #mustBeBoolean situation, another problem is that  
the .image then freezes (might be caused by something else).

Asking for (HydraVM isHydra) in the #startUp methods helped ;-)

/Klaus