GPS lock not working

[nmath]

I'm unable to acquire GPS lock at all using BB Maps. I keep getting the "Unable to acquire GPS lock" message. I did find a few threads that discussed issues like this but didn't provide a good enough solution.

My phone didn't come with Google maps installed - should I be installing this? Also, isn't the cell tower based positioning at least able to provide a coarse location? I do have a data plan but since I'm new to BBs I don't know how to check whats broken here. Thanks in advance for any suggestions.