Problem with publishing web pages

[Micosev]

Hi,

I have updated some of the pages on my website but each time I try to publish them I get the following error message 'This filename is already in use by another subdirectory'.

As I am new to website building, I simply don't understand the solution given in the 'help' file.

Can someone please explain in very simple terms what I need to do to be able to publish these amendments?

I am using Dreamhost and NVU.

Many thanks.