Disclaimer: Please note that getting this error is a serious hint towards an unstable system (in my case it was caused by a faulty hard drive). While the solution steps worked fine on my system, please create and test a backup of your system before trying...

You can use this to generate complex (as well as simple) certificate requests that satisfy pretty nice scenarios. For example, you can add the subject alternative names to the request that match all the web site names your certificate shouild be used...