NiosII IDE debug mode

Hi I am new to NiosII IDE.

Currently I'm using eCos for the RTOS of my application.

And using NiosII/f.

My application was written in C. And once it start run, it runs threads.

I'm using NiosII IDE to debug the application.

When I run the debugger, it seems run okay.

Then I suspend the thread to set up break points.

After that I trying to go through my program by using Step Into/ Step over/Step return. But it doesn't run line-by-line or step-by-step debugging mode. It complains that

//

C/C++ File Editor

Source not found

Can not find the file 'd:\altera\kits\nios2_60\components\ecos\ecos-current\packages\hal\nios2\src\hal_misc.c' in the specified source locations.

You can attach a new source location by pressing the button below

//

And ask me to attach source. But the file is something relate to eCos file which I don't intend to examine.

I only want to examine the application programe not the RTOS.

And 'Step Into/ Step over/Step return' is not available to push.

when I set up the break points, it never stop at any of those break points. What have I've done wrong?

Could you give me some advice for this? or any application/tutorial note for NiosII IDE debugging? ( I've got NiosII IDE help system note but it wasn't very helpful to solve this particular issue.)

By the way, I've set up -O0 for non-opimazation of ecos library from ecose configure tool already.

Thanks in advance.

Yong.