In reply to jkarran:
Actually quite likely for the temperature to be a factor too - it's a bit cold where I boulder and I seem to remember the rubber being 'matt' and soft a couple of months ago and now it's shiny and hard.
I definitely don't think it's worth getting new shoes - apart from being hard and shiny the sole looks absolutely fine (obviously there is some wear) and I don't climb hard problems anyway. My technique leaves a lot to be desired so I can't blame the shoes!
just a bit annoying at times as I slip on problems that I used to do easily 4-5 weeks ago but as you say, I should be able to adapt.