On the Stubbles blog, Frank Kleine offers some advice to developers looking to use the Reflection API - "don't trust it".
If you try to get informations about parameters from methods of internal classes - forget that. Examining several internal classes my key findings are: either there is no information about parameters available and the reflection API says the method does not have any parameters, or the information about the parameter is wrong.
He includes code examples along side the output from the script to illustrate his point.