WordPress 2.0 runs a lot slower and uses a lot more CPU resources than 1.5 in a Windows 2003 Server with IIS. WP 1.5 creates a spike in CPU usage, but WP 2.0 uses 100% of CPU for several seconds each time it has to serve a page.
There is no difference disabling or enabling the caching system. Maybe it's not working, or not working as it should?
Could it be a configuration problem? Shall I change something in IIS, PHP, WP...?
PHP version is 4.4.1