Anyone know anything about how broadband actually works?

well, it's a d-link dir-615, it is sold to be used with ADSL too, so presumably the worst case scenario is you'd need to flash the firmware?

anyway, I looked into ADSL modems and it's not worth splashing the cash on one so will carry on using my bebox.

Just looking at its pics it looks like a normal wireless router to me. It doesn't look like the little cable-specific box I have.