MonoX blog Web parts (and many others like profile and groups) are using "rewritten" URLs - they do not have the .aspx extension - and you need to set the "wildcard mapping" in IIS so it could catch all requests, including the ones for "extensionless" resources. This feature is crucial for SEO and many other techniques. Note that this has to be done for IIS 5.1 and 6.0, IIS 7 can handle this automatically, via Web.config.
By default, only the .aspx and related files (.ashx, .asmx) are mapped to the ASP.NET runtime. You can change this by following tis procedure:
- right click on the Web site you want to administer, Properties, Home directory tab, Configuration button. Copy the executable path from one of the existing ASP.NET extensions (.asax, for example). Click on the insert button, paste the executable path you copied in the previous step, and uncheck "Verify that file exists". This should fix this problem