I'm not sure how it would cause problems with ident, except if your friend changes settings. If you didn't change anything it is weird how it didn't work one day, then did the next - another possibility is it being a server issue, that would actually seem more likely than your ISP.
What do you mean by "servers' url pages"? mIRC's servers.ini can be found at
www.mirc.co.uk/servers.ini but if you mean a server list for your IRC network, type
/links or check out their website. Or did you mean something else?
Regards,