According to Debian's Web site, you have the correct source:
http://packages.debian.org/testing/b...e-2.4.27-2-686
Did you get the sources from Debian, or somewhere else. I tried sources from kernel.org, and was unable to get my wifi card working. Once I used apt-get, I compiled the new source files, and was able to get my wifi card working. The images, sources and headers from Debian also include the Debian kernel patches. I am not exactly what that means, but was told that was keeping me from getting my wifi card working, and it was.
Also, make sure you are doing a complete compile. Just uncompressing the source files are not enough. Here is a link to one of Debian's source compile instructions:
http://www.debian.org/doc/manuals/re...kernel.en.html
The one I used is from this forum and was written by m_yates:
http://www.linuxquestions.org/questi...radeFrecompile
I followed it line by line except I left out the Debian logo and any entries for win4lin as I am not installing that. Retrieving the source from debian with "#apt-get install kernel-source-x.x.x, and following the rest gave me a good install and everything works.
I hope this helps. Good Luck!