Progress Update Problem

I am using P6 and face a problem. When i update the progress, the activities whose %age is between 0%-100% (Like, 50% complete, 70% Complete etc), the bar against such activities in no more remains continuous but it split into 2 parts, 1st part for completed % age and 2nd part for remaining (or critical) % age and there is a gape between these two bars.. I do not know how to overcome this problem. Because the gap between bar seems like there is no work on this activity for some period of time but this is not the actual case.