Disappearing features in "New Part"

Hi all,
I'm having some problems creating multiple features within anassembly-created path (i.e., one created usingInsert-Components-New Part...) in SW2008.

The assembly-created parts are typically cables between componentsin the assembly, and contain swept features (one sketch for thecable profile, one for the path). I'm finding however that defining2 or more sweeps in a single part doesn't seem to work - one orother of the sweeps has to be suppressed for the other one to bevisible. In some cases the path sketches have coincident endpoints,but in others there doesn't seem to be any relation between them(other than sharing the same sketch plane). The assembly has norebuild errors or warnings.

Can anyone explain what's going on here? At the moment each featurehas to be created in a separate part, which is a pain. Thanks foryour help.SolidworksAssemblies