Who knows? Too many variables involved. The distance from the light to the computer? The frequency the computer communicates at? Any RF chokes on the light's cable? And so on... What kind of Cateye computer are you talking about?
Firstly, if past MJ designs are any indication, full-brightness mode in MJ light is not PW-modulated, meaning that it will produce no interference. Secondly, if past MJ designs are any indication, it will interfere with your wireless computer in any reduced brightness modes.