Saw your post in the Hall Effect thread. For the record, I don't think direction sensing ever actually worked with the 2008 GTS. If you look at the source for the GearTooth class in WPILib, the comments suggestion that the direction sensing was something to be worked out in the future.
Code:
/**
* Alias for counter class.
* Implement the gear tooth sensor supplied by FIRST. Currently there is no reverse sensing on
* the gear tooth sensor, but in future versions we might implement the necessary timing in the
* FPGA to sense direction.
*/
That comment may be out of date, but I wouldn't count on it.
There's similar products out there, but I have no idea how easily obtainable they are. Here's an example:
http://www.spectecsensors.com/html_p...re-sensor.html