i am having a problem with a legacy CGI application written in C/WINAPI

it essentially is a notification callback to receive google checkout notifications as an HTTP upload (application/xml)

it is working for the most part and when i use a simple test program it works fine as well but when google sends larger xml files (more than 1K) i get the proper content length but read file doesnt return all the bytes.

if i send the same file from my test program it all works fine.

tried all kinds of things but am running out of ideas

Anyone has any idea what i can look for?

thanks

Mike