Why are Github project document page urls case sensitive? What are the negative effects?

I Just uploaded a sample index.html page for my github project repo gh-pages branch. However it seems the url used to access the documentation is case sensitive. The correct url is as follows,

http://harindaka.github.com/ASPTokenInput/

However if I use the same url in lowercase github displays a page not found message. i.e.

http://harindaka.github.com/asptokeninput/

1. Why is the URL case sensitive?
2. Will this negatively affect search engine visibility and browser caching etc.?
3. What are the disadvantages/advantages of a case sensitive url approach?
4. Does this mean some other project can have the same name and url in a different case on github? (shivers :-O)

Thanks in advance.