I have just recently had my hands on the new Office and it is a problem
- though not just with this extension. When you save a document in the
drop down box you can chose which extension to save as. There is a
choice to save as .doc.

Over Christmas holiday a local real estate agent was trying to wrap up a
contract. She completed her end of the contract and emailed it to the
client. She had just purchased a new computer with Vista on it. The
person she emailed it to works for a very large oil company and their
internal email security software stripped out the document because of
this new extension. It took some time to figure out the problem.

I installed OO on her machine, copy and pasted into OO Writer, did a
little format clean up and sent it on its way.

Im sure MS is just doing that to keep MS users paying for something.