Problem with Automatic Page Alias Name

This hasn’t happened on other site’s i’ve used ModX for...

I use friendly URLs and have automatic alias generation on... when I now create a new page the alias that is generated has a "1" appended to the end of it.

My past experience has been like this:

- create a page called About Us and the alias would end up being about_us

Now it generates about_us1 as the alias.

Anyone run into anything similar to this?

sorry for my stupid question:
do you have another document with alias about_us??