Clearing run history

My Computer seems to clear the Run history i.e. every time I go to the Run menu it's memory is blank, as far as it is concerned I've never used it before. How do I stop this,i.e. how do i get it to remember what I've run before?

are you using any 3rd party programs to clean your pc? i use mrublaster, which clears the history. another one is Ccleaner, which wipes all traces.
http://windowsxp.mvps.org/runmru.htm