Issue in building firmware

[Google Code Exporter]

What steps will reproduce the problem?
1.first I used the firmware modification kit from google code to extract the 
firmware, then i make changes to it and try to rebuild it.
using the command 
./build-firmware.sh firmware workingDirectory/

2. Then i upload the firmware on the Linksys WRT54G router using tftp.
I do not get any errors but my firmware does not work once uploaded.

3.If i upload the original firmware without any re-build it uploads and works 
perfectly.

What is the expected output? What do you see instead?
The firmware GUI should be accessible, but my router goes into a bad flash.

What version of the product are you using? On what operating system?
my router is Linksys WRT54G and my firmware is DD-WRT v24 micro generic

Please provide any additional information below.
I'm using Linux Ubuntu 12.04

Original issue reported on code.google.com by [e-mail] on 25 Dec 2013 at 11:16