I just tried it with EE7.9 ( C# 2005 ) and it does the same. Will see if I can find something.
Here is a helpful knowledgebase article on Microsoft's developer site:
There are several document events that return a value, which is not supported with the .NET Delegate event handling mechanism.
You will need to use the IConnectionPoint interface to sink Expedition events in C#.
You sure it's not some threading issue?
Have you tried creating your event sink as a com object and loading it via VBScript?
I will try it, but first I have to learn how to create my own com.
Hooking on event in vbs ( efm ) works OK, but has another issue - http://communities.mentor.com/thread/5143
So I can not use it.
I also tried
pcbBrd.OnDisplayViewExtentsChange += new _IMGCPCBDocumentEvents_OnDisplayViewExtentsChangeEventHandler(pcbBrd_OnDisplayViewExtentsChange);
and with the same result.
So it looks like any event, which will be hooked by external C# ( still not sure if other languages, e.g. not .NET, have the same issue ), is blocking the placement.
Everything else in Expedition looks working ( route, draw ... ), so why it creates such a problem with placement ?