Incremental build of software??

Hi, niospeople! When building software in Nios IDE a strange comment appears: "Incremental build of configuration Release for project **blabla**".

But this isnt incremental compilation, because every time i rebuild the project the process doesn't change and i wait while the system library and all those unused functions will be compiled !!

On the other hand once i made a project which was not rebuilt completely after small changes. But i don&#39;t know HOW i did it http://forum.niosforum.com/work2/style_emoticons/<#EMO_DIR#>/sad.gif (...

Does any one know the way to enable INCREMENTAL build????

Sorry for my english.