Tempfile.new -> result not unique

Hi,

I am using Tempfile to store temporary data on disk.

The documentation I've read (The Ruby Way, p353) states:

"The new method (Tempfile.new("seed_str")) takes a basename as a seed string, and concatenates onto it the process id and a unique sequence number."

however, I am testing my web app, and request after request, I end up with the exact same filename..

I worked around this by actually adding a random number within the seed string:

rand_str = rand Tempfile.new(txt#{rand_str})

however, I am sure there must be a way to get Tempfile to work properly and return an actual unique name?

thanks for your help,