[Koha-devel] OPAC login and IP Address

I heard a report from a patron today saying that they logged in to our Koha Opac, but when she tried to take some action from there she was met with an error telling her that her IP Address had changed and she needed to log in again. If it makes any difference, she told me she accesses the internet via a cable modem. I searched the koha files for the origin of this error without success. Does this sound familiar to anyone? -- Owen