Actually it looks like it is microsofts problem not chemdraws!
If you are planning to buy the latest version of Microsoft Office you
might want to think again. From the Cambridgesoft website
"Microsoft removed the ability to retrieve the original chemical data
in pictures pasted into Microsoft Word when they released Microsoft
Office 2008 (if you copy and paste a structure in Word 2008, for
example, into ChemDraw, you can't edit it). We clearly do not support
this decision, but we have little influence over Microsoft's
development activities. If you preferred the old behavior in Microsoft
Word, we strongly recommend that you contact Microsoft and tell them
that. Until/unless they restore this feature in a future version of
Microsoft Word, you will need to save the ChemDraw files as separate
documents. Of course, if you continue to use an older version of
Microsoft Word that has this feature, you can continue to use it as
you always have."
>> Stay informed about: No copy-paste between Word 2008 and ChemDraw