Serious Build Permission Issue

Ok well I build and sell Avatars. I am currently working on updating 6 of my previous avatars to redistrubute to my consumers. For my tiger avatar, I have taken the orginal avatar and am working out the new modifications from that. Everytime I take a piece/part off to work on, modify it up a bit, then take back into inventory it becomes either no mod or no transfer for me! When I am the creator and owner of this product how am I loosing my own permissions to this item??? There isn't any newly added scripts or prims created by someone else. I have a new updated Tiger for my consumers that I can't transfer out to anybody! This is entirely frustrating, ecspecially when your business relies on your ability to sell your own product lol. PLEASE HELP! I've written bug reports and have heard nothing. Is this happening to anyone else?

known issue:
Attachments can lose permissions if you edit their linked parts for various reasons, even if you own the parts.
Commonly it is due to a script that is included in one child prim of the linkset, like a blinking eye script, that has less permissiosn than all other parts, but it can be any element with less permissions than another element, that lowers the permission of all elements of a linkset.

People who sell modifiable avatars tell customers to alyways keep a backup copy before modifying the avatar parts.

Well, let me explain again, I OWN and CREATED these parts and objects. I am creator and owner of all that exist in these avatars. There is not another added script or anything created by someone else. These prims began and ended with me. Although it decided to take permissions from me before I could sell said product which I CREATED and now I can't transfer for some reason I lost permissions of my very own things/creations. Does that make more sense?