Humax 9200T recording on top of previous recorded programmes?

My Humax 9200T has started recording on top of previous recordings. For example I set The Fixer to record which was ok but then when I set another programme to record it did it over the top of The Fixer. In the recorded programme menu it still says The Fixer but when I view it it is the second programme. It is also showing multiple recordings of the same programme in the recorded programme menu.
Any ideas welcomed. Thanks