It might make a difference what you are copying the content from. If you have opened a document that was created in a version prior to QuarkXPress 7, the document "flow" could be different than in a new 7.x document. We do this so that we can make updates to features that affect text flow for new documents, but still allow older documents to be opened without reflowing.
Open the document you are copying from. In the Open dialog, check the version Created. If this is < 7.0, then there is a good chance that this document is saved with a legacy flow attached. (It doesn't always as the version a document is saved in does not equal flow code version.)
Options...
1. Migrate the Old: There are improvements in the new flow, so you could choose to migrate a document or template to the new flow by holding the Option key when clicking Open in the Open dialog. (You can also hold the Option Key when dragging a doc to the QuarkXPress doc icon.) This will open the document using the new flow.
2. Migrate New Only: If you wished to keep the original flow in the original doc, but use the new flow in the copied documents, there are no adjustments as you are experiencing that behavior right now. However, I would run a test to make sure this is indeed the issue at hand. Try Option+Opening the doc as in option 1. Does it flow differently? While this is open, try and copy/paste the content into a new doc. If there is no reflow between the two, then this is the issue at hand.
3. Keep the Old: If you wish to preserve the older flow, you must retain/create a document from the same version of QuarkXPress. So, say your original document was a 6.x document. You could launch QuarkXPress 6.x, create a new blank document, save it, and open it in 7 and copy/paste. You could keep a blank 6.x doc to use as a template if necessary. Or, you could duplicate your original 6.x document, then open it in 7 and delete any unwanted content.
Hope this is helpful.
Scott Wieseler
QuarkXPress Technical Product Management