PNG file format and Fireworks

Hello,
Back on topic about the use of the PNG file format in Fireworks and the main conflict that can occur (if web developers use the images of the same format for source files and compressed destination files)  I wonder, if there is any appropriate solution. 
To my mind, the only way to solve that conflict is to change the extension of the PNG file used in Fireworks to something unique. But this method is not so great as it seems. 
What do you think?


Sally Catlett,                          Astra Web Design Company
sally@astra-design.com          http://www.astra-design.com