EEs not locked?

We have a union payroll consisting of about 10 guys in four business units. All have hours this week. One business unit, 807, has four guys in it. We ran pre-payroll. If we bring that union up in Employee Profile, three of the four guys do NOT show in fuschia as locked in the payroll. (They are in black.) Any idea why they wouldn't be locked (colored in fuschia)? Have you ever seen this before? A reset and a rerun of pre-payroll shows the same way. It is not a big deal, but it was surprising.