Problems using Logitech Pure-Fi 'Anywhere' speakers with iPhone 3Gs

Have recently acquired these Logitech speakers, which have wonderful sound and great volumne and a pretty good battery life (although I haven't fully challenged this aspect), There seems to be one problem, which Logitech are not too keen to discuss. The Speaker turns itself off mid tune, and this is not necessary for the music not to be playing - if there is a constant note or sound field playing they/it can still turn itself off. Logitech suggested I might not have the latest software loaded - not true I do. I have tried another fix, which comes up on their forum, but this still hasn't worked. Has anyone had similar problems? Know of a fix?