After several issues with the Oregon Scientific WMR-200 I finally bit the bullet and replaced it with a Davis Vantage Pro2+
This also lead me to looking at other options for recording the data and I decided to go with Cumulus MX (currently in beta) from Sandaysoft to replace the WeatherCat software I was using. Whilst Cumulus MX does not have all the features of WeatherCat, it looks like it is heading in the right direction and it appears to be following a lot of the implied standards for recording weather data so it make it easier to integrate into templates that are already available.
All my old data from the WMR-200 has been saved offline, but due to the excessive amount of problems I had with it, I decided not to import the data into Cumulus so I have effectively started the statistics from scratch.
To anyone who may be interested in setting up their own weather station, I would recommend you don’t just run out and by a low end or even mid range one. Hold off, save your money and when you can, buy a higher end one. This is particularly applicable to someone who wants above average quality of weather readings.