Huh, problem solved.
I made mistake trying to put command line option under "Custom Build" tab instead "Global" tab.
So,
Project>Built Options>Project>Global Tab>Additional command-line options (link-time only)
In my case, --ROM=default,-C000-FFFF
and it works great now.
Thanks for your time and special thanks to Nebojsa, who helped me to solve this problem.
Btw. Great bootloader tool.
I made mistake trying to put command line option under "Custom Build" tab instead "Global" tab.
So,
Project>Built Options>Project>Global Tab>Additional command-line options (link-time only)
In my case, --ROM=default,-C000-FFFF
and it works great now.
Thanks for your time and special thanks to Nebojsa, who helped me to solve this problem.
Btw. Great bootloader tool.