I figured out my problems...
I made such a stupid mistake.
While building my game I used the old PHAL.lib
It's all because of laziness - once I moved the PocketHal.lib files in the \lib folder (where PFrog.lib files are) from the \lib\win32 - I was so lazy to add another one directory in the library files menu.
So patching with new PHal hadn't affected all those old files.
But now I've got good performance gain upgrading from 0.7.5 to 0.7.7c.
I'm really thankful for this Treo issue.
Sorry for complaining about PHAL