VC6 was notable for simply discarding OutputDebugString output when things got busy. This was a problem I used to suffer from quite regularly, and it caused me

VC6 was notable for simply discarding OutputDebugString output when things got busy. This was a problem I used to suffer from quite regularly, and it caused me a lot of bother. I have no idea just how they managed to utterly fuck up the performance in VS2002 and later, but it does at least capture every last char of output, if you have the patience to wait for it. (Perhaps on modern multi-core multi-GHz CPUs the VC6 approach is reliable enough, assuming it's some timing issue. But I have to say that I do prefer the VS2002+ tradeoff. Wish somebody would just fix the whole sorry mess though.)