To any reading these reviews - there was a compatibility problem between the Robi and the Apple iPod Classic and 3G Nano models which appeared when Apple released version 1.1 of the iPod software for these models. Version 1.1.1 did not solve this. Version 1.1.2 released on 30th April 2008 does solve this, and the Robi now no longer turns off after two minutes. Thanks Apple! I can now listen for hours at at time. One minor new problem replaces that old one. If Robi is in DAB or FM mode and you use Robi to switch off your iPod, then you will generally need to use the iPod controls to switch back on again, and it may require a couple of On-Off cycles. No such problem if you switch off with Robi in Remote Control mode.
I note that one reviewer found very poor battery life using Robi on his Nano. I can only assume that his battery was already pretty worn out. I can get quite a few hours listening when powered from a 3G nano.