Yes, it means your PC is haunted. Call the w[IT]ch doctor.
But really now, offhand it sounds like a graphics driver issue. So, this ghost part is actually open in another window? Pretty weird.
Thanks for your input, I agree it must be something to do with the graphics but ASFAIK all the drivers are up to date. I was hoping someone might know what it was so I could avoid doing it in future.
A bit more detail if you are interested:
It always goes after a system reboot.
It sometimes goes away after closing and restarting SE.
I can discern no pattern in when it occurs - sometimes several times a day, sometimes none - sometimes assemblies with the ghost, sometimes parts have the ghost - sometimes assemblies are the ghost, sometimes parts are.
In fact I think the only thing I haven't seen is it appearing in Draft/being an appearance of draft(but then I don't spend that much time in draft at the moment anyway).
No it is not always the same part.
I have seen it be:
1) very simple parts (like a plain cylinder),
2) complicated parts (equation driven swept surfaces)
3) small simple assemblies (half a dozen simple parts)
4) small but more complicated assemblies (adjustable sub-assemblies & more convoluted parts) <100 parts total still though.
It is onboard, I was witholding that information in case anyone had any other suggestions - upgrading might be a hard sell for me here (I don't hold the purse strings).
I would like to say I have a normally acceptable experience, but it would be a lie. I have a lot of restarts, and a surprising amount of trouble simply selecting things on screen.
Anyway, to give you all the details I have easily to hand:
8 Gb ram
A quick web search review of that graphics setup with cad wasn't promising. The rest of your system is decent.
I don't know, even a couple/few hundred bucks would be an improvement.
They're paying you to waste time with the problems you're having. I'm not saying that's definitively the cause but you should eliminate it as a possibility IMO.
Under Solid Edge Options - View tab - Application Display, remove the Automatic Selection check mark and try changing the various options from the list just below it, restarting Solid Edge if required, each time. It is a shot in the dark but just might work.