oil leaks (auto box )

well drove my 96 4.0ltr range tonight for the first time , as being brought as a non runner , and it woz great... having replaced the exhaust crank shaft sensor and air flow meter ... BUT as i woz getting closer to home i could smell hot oil , on a closer look it woz dripping trans fluid on the left hand cat which woz running down under the heat shield from an unknown place , wot woz realy worrying is that while i woz undernearth trying to see where it woz coming from , the fresh fluid woz igniting as it hit the now very hot cat (which scared the **** out of me ) , .. i let it cool and pulled the shields down and re started it and left it running for a further half an hour and it has,nt dripped at all .. could this be caused by over filling by the previous owner . has anyone else had the same sort of problem

Yes that what happens when the box is over-filled when the engine is stopped it comes out of the dipstick tube (don't ask how I know...)

I was told it catches fire, seems like it does!

You should check the level again, it's probably still too high; it takes ages to drain then check as you have to run the engine when cold, but its worth getting it right.