Debug in Release

hi, this time i talk about something i "bump into" while trying to run my engine in release mode (after i changed all engine class design and such) and get a crash into my face, oops not good.
at first i thought it something i mess with, i had no clue where to begin because the change was so big so i start shooting all over with no luck.
so i created exception handler lib which will catch exceptions and just before it will crash it will generate two files:
1) log file about the stack, modules, user, and the must important is the eip, which is the instruction pointer where the crash was happened.
2) mini dump file which is generated using dbghelp.dll, this is basically a snapshot of the program before it crashed, and it can be opened via vs or windbg and it will show you the exact line that cause the crash (very useful)
after having this kind of tool i started debugging and check what the hack cause the crash, i saw that there was uninitialized pointers such as d3ddevice interface, which wasn't make any sense because in the log i saw that textures and other data was loaded.
this turn on the red alert, what is wrong with my code, and why it is working in debug and not in release (and it was working!!)
i watch the engine log and see that the constructor of some managers was called twice which wasn't possible and make sens because they are singletons!! after digging a bit i notice that if you create static inline singletons (scott mayers singletongs) the compiler (which is vs2003 not 2005/2008) generating wrong code when optimization is on, and make the constructor called twice or more if you include the header in more then one object file and you call the static inline function that return the singleton instance/object.
if you move the implementation to the .cpp code the compiler generate "good" code.
because those managers are heavily used i didn't want the overhead of the function calls, so i dig a little bit more and i found a trick that works.
NOTE: this only happened on vc6 and 2003, in 2005 they fix the problem.
so if you are used to create singletons like this:
class CTest
{
public:
static CTest &GetInstance()
{
static CTest instance;
return instance;
}
}
you should now use this trick:
class CTest
{
public:
struct tDummy
{
static CTest &getInst()
{
static CTest instance;
return instance;
}
}
static CTest &GetInstance()
{
static tDummy instance;
return instance.getInst();
}
}
vc2003 deals fine with static var which contained in a non-static inline method.
so what i found is that i didn't mess anything and the code was fine and the compiler wasn't
after all it was good practice to wrote the tools and i think they will be useful in the future - i hope i wont need to use them :)