Ah, yes if they already have 3 ships and get another corp ship they won't be able to activate it as it's counted as a 4'th ship.
The VIP corp member is not related the the SOL VIP status that grants ship licenses, two different things.
This should no longer be a problem if the unlimited license update goes trough, will try to speed that one up:
http://forum.astro-galaxy.com/index.php/topic,8351.0.htmlUntil then, they have to keep under 3 ships including the corp ship or get VIP status from left menu.