A random guess - have you disabled the bluebooth interface on the NXT block?
Or have you tried a very simple program to verify the assumption that the irregularity roots from the NXT block, NOT from your robot?
For instance, use a known good cable (check the phone jack-like clip carefully and make sure the connection is secure and tight), connect NXT block to the motors without the tires and also connect a touch sensor and a light sensor. And then write a very simple program or create a sample program from Robot Educator.
Does the battery contact pins work well with the rechargable? - you may temporaly install the AA batteries just for tesing
Let me know what you find out from the test. Thanks.
--- On Tue, 11/3/09, Sherene Silverberg <[log in to unmask]> wrote: