Unfortunately that's no joke. In old versions of the Spider USB driver, when you tried to hack the driver and change the PCI IDs to make a generic USB card work, you'd find that the driver had erased the RDB info. It seems Poseidon detects this and tell you before you reboot.
Must people don't actually find this funny, since it endangers your data in case of some malfunction (RAM, memory access) - it has been reported, that this 'function' is not included in newer Mediator drivers any more.
Personally, this issue has disqualified Elbox from me ever buying anything from them.