Could the inconsistant results due to less than perfect support or didn't use 2s self-timer with pre-fire? I have found the 2s MLU is a great way to reduce vibration no matter how rigid the tripod is. Have you tried a more stable tripod/head? The best way to make sure precise focus is a magnifier. But if you are certain there is something wrong (left/right sharpness & light-fall-off look different are indications), return it to Kerrisdale is the best option imho.
Alan Chan http://www.pbase.com/wlachan __________________________________ Yahoo! Mail Mobile Take Yahoo! Mail with you! Check email on your mobile phone. http://mobile.yahoo.com/learn/mail