I saw your list of upgrades and I noticed it said something about the center shaft. Did you upgrade to an extended center shaft? The extended shaft gives more clearance between the blades to prevent blade strikes. There are several places that sell them here is a link to on of the sites
[link]http://www.slickzero.com/Merchant2/merchant.mvc?Screen=PROD&Product_Code=ESL020&Categ ory_Code=[/link]
And here is some ones home made solution on rc groups
[link]http://www.rcgroups.com/forums/showthread.php?t=633819[/link]