Problem solved!
I was actually to do with the settings on the actual laptop, not the router. The router can be changed to static IP addresses, but only those incoming from the ISP, not for each individually connected machine.
Anyway, changed IP and DNS values in TCP/IP settings for the wireless connection on the laptop to specific values instead of 'auto-detect', so now it doesn't ask the repeater to assign them, which it can't do.
Job done!
