How to prevent style change to Normal when pasting in W2007

How can I prevent W2007 changing a style to Normal when pasting content into
another document that has the same styles?

There were 4 paragraph styles used in a table in my source document. None of
the 4 styles are based on Normal. These styles did not start in this file; I
copied them in via the organizer, then applied them to the table's contents.
When I copied the table from the source file into my target file that had all
these same styles, Word changed all table paragraphs to Normal style. Why is
this happening and how can I prevent it?

Further, in my Word options Advanced, the Cut, Copy, Paste group shows
"Keep Source Formatting" for "Pasting between documents when style
definitions conflict." In reality, there was no conflict, but this seems to
be "insurance" to prevent the very thing I experienced.

If anyone has ideas about this, I'd like to learn why this is happening and
appreciate a remedy.