When "Analog Encoder" is selected the wraparound is tracked (1023 => 1024). It sounds like "Analog Potentiometer " is instead selected (so 1023 => back to 0).
Can you grab a self-test screenshot as you manually rotate (or just straight drive) the swerve module using the RIO web based config? That will tell us what the reported sensor position is before and after the wraparound and confirm the selected feedback device.
Is talon firmware 1.4? (
http://www.ctr-electronics.com/talon...ical_resources)