Problem converting timing to int under 1 hour

[slimedia]

When I set the timing (settings > B5) and go to start scheduled tweeting, it only works if I set it in hours. If I set it to any minute value it gives me the error(?) of "Exception: Cannot convert '15.0' to int." (also 1.0, 5.0, 10.0, 30.0) with no further details and won't tweet.