AutoCAD Civil 3D

[#1]

I am having a nightmarish problem with sub assemblies.

I have a drawing that contains seven assemblies. Suddenly all the sub assemblies for all seven assemblies have moved to 0,0,0. Has anyone experienced this before?

I am running Civil 3D 2008

Windows xp with sp3 installed

Thanks for any help

[#2]

Any chance these assemblies are referenced from other drawing? Can you upload your drawing(s) for us to look at? 

[#3]

Sorry to bring up an old topic, but this has happened a few times to me now.

From time to time, without warning, all of a sudden some of my subassemblies detach themselves from the assembly marker and move themselves to 0,0,0.

I am not sure whats triggering it, but it is a right pain as the only solution seems to be to reattach each subassembly back to its marker on by one. (Moving them all together spreads them out even further).

Any suggestions on this?