wierdest (annoying) C++ bug

I was recently in a tour of a professional games company and asked the question 'what was your most irritating beta bug?', he mis-interprated the question and answered 'any that gets released into the final version'.

My most irritating bug was having a loop->
for(i=0; i<10; i++)
{
//do what I had to do
if (this happens) {i=0;} //reset 'i' in order to start the loop again
}
What I didn't realise was that when I reset 'i' to 0 the loop was incremented after that statement and actually started on 1

you call that annoying? you should see the bugs I deal with

its often the smallest bugs that cause the biggest problems.....

this is one of my favourites...

if(y=2 || x=4) {...}

heres another....

while(1);{....}

I would love to hear them, that way the rest of us don't do the same mistakes :)

And I must admit I have done the if(y=2); mistake