Help with transparency and SDL

I am currently trying to write a bomberman game for SDL. However, I can’t get transparency working with the game. I’ve written a fairly small test case demonstrating the problem. All the source is up at

Inside the BomberLAN module, in the Tests subdirectory, the problem is shown in TransparencyTestMain.cpp. Running make from the BomberLAN directory should create the tests.

I am attempting to make the transparent color the pixel at the top left of the image. However, The transparency doesn’t work at all for the first four images in the test, and the last 4 animations flicker a lot, although there is some transparency works (I’ll have to fixing small color changes in the background image).