Bug in full screen slide show: Speed-values under 1.0 don't work, they will be zero. Maybe a german problem because of ","?

I wan't to do a full screen slide show with changing images under one second. But this doesn't work because every value under 1 will be 0. Maybe this is a german problem because we use "," instead of a ".". But I can't use ".", the field doesn't allow this. Is there a workaround or a bugfix?

Thanks