Hi Dennis & thank you for your reply,
Well the issue has cleared but no doubt will rear its head again when I least want it! Thanks for clean up link (Oh dear more software downloading more maintenance).
Here the punch my workstation packs:
iMac late 2012 21.5 inch
Processor 2.9 GHz Intel Core i5
Memory 8 GB 1600 MHz DDR3
Graphics NVIDIA GeForce GT 650M 512 MB
Software OS X 10.9.5 (13F34)
Thank,
David