I turn off my arranger and cover it with the plastic cover EVERY break, wash my hands after load in (if I've got time), and pack it first and get it out last.....
So far, virtually NO problems (and I gigged my G1000 outside on a beach in FL for 4 years and played it for 8 yrs in smokey clubs with no problems!!)
A little analality goes a long way!
Try
http://www.lecover.com/Cover_Co./Home.html for good quality covers. I've bought one of his for every keyboard I've owned since the 80's, and always got top dollar for them (the keyboards) on re-sale. Plus, it shows you cared for it.....