gdb ignore iteratotr++ operation

I start my app in codeblock with cmdline arguments with gdb. App terminares before reached breakpoint. I run in stepping mode. That code:
ParamList::iterator p = iParamList.begin()+1;
gdb see as:
ParamList::iterator p = iParamList.begin();
After that I download build and install gdb 7.12.1. Nothing changes. Also I run gdb directly: gdb myapp -options and got same result. I run app with that params and it crashes after that statement. To track path to crash I print to console messages like cout << "here".
My build enviroment : msys with mingw(not mingw-32/64) 5.3.0
How to deal with that?
Source here - https://github.com/fedor4ever/elf2e32

Always yours, Strizhniou Fiodar
Всегда ваш, Стрижнёв Фёдор