I have to set up remote debugging for a multi threaded application running on a embedded device. C++ is the language.

I've gotten so far and got the remote debugging working for a simple application, but when applying the same procedures on the multi threaded giant just don't work (the application starts behaving unpredictably when built with debug). There was no stopping of the execution (no breakpoints), just a continuous standard run, just with debug symbols.

What would cause a failure in debug mode in this environment? (once again, no breakpoints in debug mode, just continuous running)