Why Do My Items Keep Disappearing?

I am working on a sword, which obviously works as an attachment....

It keeps getting permanently deleted. It does not go to Trash, it does not go to Lost and Found, it just completely ceases to exist.

WHY?!?!?

Since it is a work in progress, I am frequently and repeatedly editing it, editing the scripts, dropping and re-attaching it. Then, after maybe 5-10 minutes when I am really starting to feel that I've made some progress, it just goes byebye. Sometimes it doesn't seem to have disappeared, but when I log out and log back in I discover that it no longer exists.

I've never had this problem before yesterday, and absolutely nothing on this machine has been changed. Yeah, I've cleared the cache re-installed SL and all of the other inane "did you try this" stuff that's asked as a first line of defense.

Is this related to the untested code changes that went out as a result of the grid attack, maybe? It seems likely to me.

[Edited to add:] On further reflection, not only am I dropping and re-attaching it quite frequently, but in the course of testing it the sword is rezzing a decent number of temp-on-rez "bullets" that are used for hit detection and the like. Perhaps this is significant? Seems like many items that rez things are having bizarre side effects, but I gotta tell ya, permanent mysterious deletion of their hard work will likely drive many people out of this game permanently.

Takuan, this sounds like grey goo fence restrictions which are continuing to be adapted as to not impair reasonable Resident content. You can see this thread for further context:

/54/90/105838/1.html

Since it sounds like you're able to reproduce this reliably, please send a detailed and comprehensive bug report inworld: Help menu > Report Bug so it can be investigated further by our Quality Assurance and Developers. Thanx.