If all of the laptops (wireless adapters) are failing to find the Wireless Access Point, I would tend to suspect that the problem lies there. You should be able to prove or disprove that by trying to connect a "known good laptop" to it.
The problem of reinserting the PCMCIA cards and Windows finding new hardware is very strange, particularly if this is being repeated across all of the laptops. There shouldn't be any problem removing and replacing these cards and Windows should recognise them as hardware that is already installed.
It is always possible that a recent Windows Update has messed things up, if the computers do get updated regularly.