Good news Andrés!
I was able to find the problem causing ESP to crash when more than 80 races are processed. I should have a new Version up shortly with the fix.
Turns out that the problem was in the HTMLgen module and not in my program after all. Every time it wrote out a HTML file it printed a confirmation message to sys.stdout. The problem is that it apparently expected this message to go to a DOS command window but my program is not running in that mode. So instead it goes to an internal Windows buffer and once 160 such Messages are printed, the buffer fills up and the program gets hosed.
Fortunately, Python modules like HTMLgen come complete with the source code. I was able to track it down, comment out the offending code in the module and, whoooha, it doesn't crash anymore.
If you're a programmer, it's times like this when you feel really good (you programmers know what I mean).
