Wordpad can definitely save mtl files, if is helpful I use it all the time along with Notepad.
I think I know what is happening...
In Windows do you have your Folder view options set so you can see file extensions?
If not, when you edit and save a mtl file, you are actually saving it as .mtl.rtf (or for Notepad it would save as .mtl.txt) but the .rtf (.txt) part will be hidden from you. So you actually think you've saved it as a .mtl but the file won't work because the extension has been changed.
If you are using Windows XP, open any folder and click on the Tools tab.
Then select Folder options...
Click the View tab
Look down the list for Hide extensions for known file types and untick it.
Click OK and you will now see all file extensions.
If using Vista or Windows 7, open any folder.
The tabs are hidden until you press the left Alt on the keyboard. Once the tabs appear then follow the same instructions above.
One of the first things I do, after installing Windows on anyone's machine, is untick the 'Hide extensions for known file types'.
Hopefully this will help save you hours of work!
db4tech
