httpd.exe process cpu overload

[pdr]

Hi,
I'm using win7 on i7 computer. I was using Xampp 1.8.1-Vc9 before and every now and then the process httpd would take like 99% of all 8 cpu's. I upgraded to 1.8.3-1vc11 just recently but it seems to happen again. When it happens, I was not doing anything with php or so. I stopped the process by going to the resource manager. Anyone any idea why this process is "taking over" my computer?
Thanks,
Peter