I bought myself a couple of the DLink DCS-930L wifi cameras.
At around $55, they are pretty good value.

They worked perfectly with my gear (Frtiz!Box 7390), but a colleague who also got one had loads of trouble with his Telecom TG585 v8 modem/router.

Symptoms were it would connect for a split second, then disconnect (when connected via wireless).
I called DLink tech support to ask if there were any known compatibility issues between their gear and the Telecom modem. They put me on hold, so I decided to google the issue and discovered that it was a known issue (admittedly with a DCS-932).

Solution is to put the modem into WPA2 mode (not the default of WPA+WPA2).

Thought I might post this here just in case anyone else has this problem!

Nigel H.