Are you in the same location where it used to work? A wifi only iPad doesn't come with true GPS ability but it can show locations to some degree of accuracy depending on towers in the area.
Just thought I'd throw this in as a possible cause as to why it's not working now. Hopefully someone will know more.
Oddly enough, while I was out and about with my iPad, I used my phone as a hotspot, and as a result, it found my location right away. It is only the home wireless that doesn't show my location for some reason...
If you have an ipad2 w/3g, do you have to be connented with Verizon or another carrier or can you use a hot spot on smart phone to make ipad work as a true gps?