Thanks for the advice but it hasn't worked so I'm at a bit of a loss why this has happened in the first place as I haven't change any settings on my mac prior to this happening. Oh well here's hoping things will sort themselves out. Until then there will be no further photo updates (sent from my iPad).
OK.
1. Open Terminal.app (Finder->Applications->Utilities->Terminal)
2. Type the following and press enter (enter your password if prompted): sudo dscacheutil -flushcache