For each file in the given changelist used for sync - a connection is created through p4.exe. The object of this less that optimal solution is issue #7618 where a 'p4 where' command is issued for ever file in the changelist and that quickly yields an error:
P4 Where Parsing Error: TCP connect to perforce:1666 failed.
connect: perforce:1666: WSAEADDRINUSE
com.tek42.perforce.PerforceException: P4 Where Parsing Error: TCP connect to perforce:1666 failed.
connect: perforce:1666: WSAEADDRINUSE
Because all ports have been used

We reverted to perforce plugin version 1.2.5 - that seem to have solved the problem as no where -G's are issued