Hi Raj,
In general DO_CONFIG_DETERMINATION method is called on every server round trip. So there is no possibility that this method is not called unless this view is non configurable or not shown on the UI.
There might be a couple of reasons in your case.
1. If you have multiple application servers you would have put a break point on one app server and the request from browser landed on another app server.
If this is the case in your landscape then use the Tcode SRDEBUG after setting the break point to activate the break point on all the application servers.
2. By any chance if you have set the parameter WCF_IGNORE_ENHANCEMT to value A which would have caused the system to ignore the Enhancements.
If this is the case remove your parameter within SU3.
Regards
Vinod