questions

This has been the most frustrating experience of my life...
for some godforsaken reason my version of gamemaker which is the newest lite mac version (v7.5.83) will not let me make transparent tile sets.
I already know that the transparent color is set with the bottom left pixel. I've set the 'transparent' checkbox. No matter how I set
those colors, the background is always visible and _not_ transparent whenever I try to build a room using the tile set. When following the
tutorial, I load the file 'tiles.png' from the GM Platform Games tutorial Resource directory and it always comes up with a green background
that will never go transparent.

What is particularly frustrating is that the transparency works for sprites and other objects.

Is it possible that the older version available for the mac doesn't support transparency for tile sets?
Is it possible that the 'tiles.png' file doesn't have the right format to allow transparency?

If anyone could either advise me how to work around this (I have googled the topic to death, so the basic advice about the program
mechanics will not really help), or confirm that indeed this version of the program will not produce transparency with the tutorial tile set,
I will be eternally grateful to you. Even if you have a mac and v7.5.83 of GM Lite and you download the tutorial and load 'tiles.png' into
a background and you get nice transparency, that would be helpful because I'll know that it has to do with my particular setup.

Sorry for the long post, but I'm desperate to get this to work!

Thanks,

Questions (L)