"because parentheses {} [sic] don't match. Therefore, it is difficult to say what's wrong with the code"

It is extremely difficult to say what's going on with your code - let alone what might be wrong - since all the formatting has been lost - rendering it almost unreadable!

As Mahmood has already said, you really need to use the <pre> and </pre>HTML tags if you want anyone to seriously look at your code.

What optimiser level are you using?
Don't forget that the C51 optimiser has options to merge common entry- and exit code for fucntions...