I'm personally running IIS7 and don't have a problem with this. I did some quick googling for this and you might try reading this:
http://www.tek-tips.com/viewthread.cfm?qid=1641594(http://www.tek-tips.com/viewthread.cfm?qid=1641594)
Specifically the 2nd to last post.
Another person reports the following as their fix:
Resolved
OK, I have resolve this problem, The answer is simple and annoying, I'm using Windows 7, the main problem is UAC, every time i save the php.ini, it's saved to the Virtual Store instead of the original location (because i dont use administrator right when editing) I tried to edit the php.ini under administrator right, and Boom! worked like a charm
source: http://stackoverflow.com/questions/7388765/iis-7-5-express-php-echo-shorthand(http://stackoverflow.com/questions/7388765/iis-7-5-express-php-echo-shorthand)
Either way this is a server configuration issue, not an OST issue. :) Good luck.