Using NVU when I create a web page it converts my simple file names adding %20 and it's a wreck to read in source.

Is that really necessary?

%20 is the code for a space. If you have a space in the file name, then most applications and web browsers will insert a %20. To avoid it, try using underscores (_).

Thanks so much, I thought I was losing it.

Underscore it is!