Yes they are interconnected the if the speedometer dose not read then your odometer will not increase. Most likely a wiring problem or a miscommuntication between the trans and the ecm.
Run the high scan machine or scanner on your car and see if you pull a speedo gear faliure code, at that point you know you have an electrical issue then check your wiring from the speedo down to the ecm which is around where the stereo is. (the wire should be yellow with a white streak in it) If every thing seems ok there then check the wiring on your trans there are a few diff senosors and things that can influence this problem with the type of work you did so ill post more later as soon as i read up more on the problem !
[Edited by TibSkillz on May 31, 2006 4:44 PM]