SK,

"ksudavid" has very valid questions.
After reading his post I simulated your problem -
I put down two parts positioning it to the planes, as if edges of another part.
I had no problems what so ever.

I have seen / experience your problem before though but do not know when - maybe SE V17?
I am currently running SE18 SP5.

Also repeating the above questions:
1) what SE version and service pack do you run?
2) can you see your XYZ planes in your assembly enviroment?
3) can you see and select the planes from your edgebar?
4) have you tried auto connection function yet?

Otherwise the use of a fictional part can be used.
I use this technique and fictional edges alot if I need to do something in a hurry and it is for visual effect only (impressing a customer).

PLEASE give us feedback - even if it helped or not.
(It is also helpful for us if we know that we can close down a post.)
Hope to hear from you soon.

"ksudavid": thank you for contributing. Hope to "see" you soon & regularly.

Andrew: it is a valid point; we should make it standard for people to specify which SE version they are running, when posting a question.

JK: Have you come accross this problem before too?

If something is only for visual pressentation, my friend call it "eye candy"

WB