Tachometer jumpy at low RPMs after firmware reflash
 

While I was trying to load a map onto my MSPNP 94/95, the firmware got corrupted or something. Page 12 and 13 somehow failed to write. After a few tries the ECU just stopped responding to Megatune. I was able to reflash the firmware by jumping the BOOT jumper and all, but now, strangely my Tachometer is misbehaving.

Above 2000 RPM or so it seems to act just fine, but below that it jumps all around as though it's getting a really dirty signal. Prior to this it worked fine. Also, in Megatune the RPM reading looks pretty solid and not all jumpy. Could this just be due to a poor connection at the ignitor plug (since I had to unplug that before loading the firmware). I did have to disconnect the MS so I could open it up to jump the BOOT jumper as well, so maybe a bad connection there? I thought the tach signal goes straight from the firewall to the gauge cluster though, without going through the ECU... right?