For some reason, my newly purchased cateye only seems to work(as in take speed ect...) when I tilt the handlebars as shown below and spin the wheel. I just cannot figure out why that is... If anyone can offer any advice as to what it may be?
If it does only work like that that's weird but, you've probably figured this, have you checked the distance between the receiver and the little magnet on the spoke? Maximum distance 5mm? Only other thing may be to try the receiver a bit higher up on the fork?
Take the head unit off the bike and move it as close as possible to the sender, make sure you get a signal, then move the head unit away. It should work in all positions upto about 70cm - 1m away (it varies).
If it doesn't, first thing to change is the battery in the sender. When I got mine initially the battery was nearly flat and I had similar (but less extreme) problems. New battery fixed it.
I reckon that you are getting a weak signal because of a weak battery and that is making the unit susceptible to interference. Something in the room is causing that and when you turn the bars you are effectively moving the computer further away from that interference.
It might be that the thing will actually work outdoors (except below power cables). You could take it outdoors and try it. It could possibly pack up halfway round the ride though if this is the case.
Anyway - stop messing about with your computer Andy and get yourself over to Hebden Bridge for the PaulB ride!