Compiler/TMS320VC5509A: Compiler ignoring code with O3 level optimization

Tool/software: TI C/C++ Compiler

hi,

I have a code which runs on a C5509A platform with CCS Version: 8.1.0.00011. The problem i am facing is that with the O3 level turned on for the project, some of the 'switch/case' statements are not getting executed. For example, i have something like:

switch(message id){
case 1:
         ....
         break;
case 2:
        switch(header){
         case 6: macro stmnt
         case 12: macro stmnt   
          ....
         case 42:
         case 48: macro stmnt    
         default: send nack
              }    
Case 10:
default:
}
Even if the header=48, in case2, the control never hits the case48 code, but instead goes to default which is right next to it(send nack). If i turn off optimization, it works as expected. Another observation is that if i add another dummy case statement after case 48 (with optimization), then also it works. The macro statements are actually function call with different parameters, and from the dis-assembly i can see that the macro statement for case 48 has not been replaced with function call as it should be and like other case statements.

Has anyone seen or experienced this before? Why the compiler/optimizer ignores this specific last case statement?

Regards,
Dileepan.