Refined testing, splitting the various CRUD activities into different test methods. Said activity took up the whole day, squashing failures as they turn up.
Regarding the dates previously, switched to using the dateCreated and lastUpdated variables as GORM handles the timestamping with those variables automatically. There is another date variable that now works fine, making the past problem a head-scratching puzzle.
Next up is the service tier. On that note, found a nice Grails CRUD example at http://infoq.com/minibooks/grails. The PDF at that site shows how to create a Racetrack CRUD.
More information here :)