Well, assuming your EGR was functioning properly before you disabled it, then yes, you should see an increase in temperatures. The EGRs job is to lower combustion temperatures (which limits the production of NOx), and so disabling it should increase combustion temperatures by a bit. I'm surprised that it produced such a noticable change though, when I disabled my EGR (which was indeed functional at the time) I noticed a slight subjective performance improvement, and no appreciable change in temperature as measured by the gauge.
Its possible that the thermostat or some other cooling system part was marginal before, and with slightly increased combustion temperatures is now showing itself as a definate increase in running temperatures. Hopefully some more experienced folks weigh in on the situation.
peace,
sam