A family of Microsoft relational database management systems designed for ease of use.
Rob,
In addition to Julie's question, are you unlinking the dynamic master to create a static master and then planning on sending the static master out to users? If so, then yes, it is very likely that the tasks in the former subprojects will move since they are now responding to the master's Project calendar whereas previously they responded to their own Project calendar. If there are any differences in calendars, tasks that are not constrained will move.
If the above is the case, one way to "fix" the problem is to find all unconstrained tasks in each subproject and put a start-no-earlier-than constraint on them. Then unlink.
John