Photoshop :: Image Alpha Channels

I cannot find much on the web about it, how to use an alpha channel. However, none of them address this issue.

I use photoshop cs3 extended.

I am using png and tga image formats

When using an alpha channel, you can set the alpha to absolutely transparent. However, when you do and save the image it removes the other channel information on the rgb channels. This is problematic because I have to use a 1 transparency value to retain my rgb channels. This causes issues as I need the full alpha but also the texture information.

This is for texture work on a game and the engine uses the alpha channel for a team color overlay on top of the rgb image. So I need all 4 channels rgb for texture, and the alpha is a team color overlay.