problem using git on cygwin

Hi,

 Am completely new to git, and following from the tutorial, to use git
for my project.

 Using git version 1.5.0.3 on cygwin (available on packages).

I am able to do the steps.
1. git init on my source
2. git add .
3. git commit

After that, a new file is created for the project and after editing the file. am trying to put into the souce.

since it is a new file for my project git repository, am trying to add it but end up with errors as follows.

$ git add project/test.c error: bad index file sha1 signature fatal: index file corrupt

could you please help me, what am doing wrong?

best regards, srinivas.