When it came out in 2006 the R5 was highly rated, however looking at one review it states :-
Ricoh proves once again that it can match and often exceed anything its rivals can produce. The Caplio R5 has a unique specification, combining wide angle and long telephoto abilities, effective image stabilisation and a usable high ISO setting, with good image quality and outstanding performance. Its only weak point is its poor low light focusing ability.
So whilst it provides excellent results under decent lighting conditions - it would appear af focusing in low light is the main problem.
Looks like you may need to upgrade, if your keen on concert photography