Thanks Jay_Jay, I found the problem now...
Also you should actually use -0,5 or -00.30 or -00:30
The latter ones don't work for now, will fix it in a minute
(got 5 min remaining
)
-edit-
Fixed I hope, Jay_Jay, could you test it?
-0,5 -00.30 -00:30 should all do the same...
Download in the opening post
(at the end of the class
)