Thank you Scott, Welch, Alan and Kelvin for your tips. I know my problem now, I have been skipping my proper maintenance, and also practises It is the operator, not the machine I guess. I could also try some new methods and solutions. Thanks. Cheers, Ling SM -- http://www.piclist.com hint: To leave the PICList mailto:piclist-unsubscribe-request@mitvma.mit.edu