How to add html file under eCos

Hi, there

I am trying to develop a web interface based on eCos. However, I have encountered a strange problem. If I modified current existent html files under eCos, they can work normally in the device. If I tried to create web page with different name, the targeted device can not be in a normal condition. However, if I copied the created content to the other existent but unused html files, everything is ok. I was wondering is there a specific limitation on the html file name? If so, how to add html files with own assigned file name? Thanks