Millisecond Forums

I'm having some trouble setting the refresh rate for an experiment. Using the arguments for the displaymode attribute (http://www.millisecond.com/support/docs/v4/html/language/attributes/displaymode.htm), I set the refresh rate to a number used by other researchers (refreshrate = 120), and I get the following error message:

120 is invalid. Value must be an integer from 1 to -1.

Why am I getting this error and why would I want to express a refresh rate between 1 and -1?