My transmission has started to slip, seem like it all gears and it don't happen very consistenly. If I dont drive it for a day or two I seam to work better. I've check the fluid, changed the fluid, and the filter(mostly becouse it was cheep). So my next step is to try a rebuild kit, probally the rings wearing out. But usatransdoctor.com talked about the gears changing were computer controled, has anyone heard of or had any success at changing the following throttle position sensor, vehicle speed sensor and inhibitor switch. Let me know what you think. Thanks

Did you find a cause for your slippage yet?
If not...is it a manual or auto trans? My manual started slipping when oil from the rear main seal started leaking.

I know this may be a dumb question, but was it slipping before you replaced the transmission filter? I have seen people not install the filter all the way on other vehicles (Fords) and it would cause the pump to not pick up the fluid and cause a slipping condition. I'm not familiar with the Nissan's filter design, so this may not even be possible with it. Just a thought.