Problem with libgd..

Hi, I don't know if this problem belongs here, but here it is: I'm using php4 to create dynamic buttons. When i call the file directly from my browser it works, when the file is called from my homepage it doesn't work. I don't see error messages and i don't know where to look for. I'm almost sure i did something wrong while compiling everything.. Can somebody help me with this ? Thanks in advance, Freddy ps: i'm using php 4.0.4pl1 with apache1.3.14 phpinfo(); says that i have libgd version between 1.3 and 1.6.1