Eclipse PHP was giving me fits. Every time I switched between tabs of files the file open/save dialog kept popping up. I tried to change file associations since I thought that was the problem but the issue remained.
I couldn’t find any posts on the web and then finally I found one. It said something about stopping Eclipse from doing previews. I searched through the options and couldn’t find anything right away. I finally followed:
Window (menu option) -> PHPEclipse Web Development -> “Browser Preview Default”.
Un-Check both of the options. After that the pop up went away.
Hope it works for someone else.