Spontaneously disappearing attachments?

Twice now (today and yesterday) my attachments (hair, attaches to chin, shoes to feet, and wings to spine), have disappeared. It's not just that they de-rezzed; it's that I looked in my inventory and they didn't appear to be attached anymore. Near as I can tell, it's a side effect of lag, or some such, because it's only happened when I was in the process of loading a fairly high-prim area. Only one of the two times did it start immediately upon teleport. Later the attachments work again, but I have to re-attach them.

I'm not sure if this is mac-specific, but I'm on an iBook G4, 1.33GHz processor, 768 MB RAM, ATI Mobile Radeon 9200 graphics, plenty of free harddrive space, etc. Mac OS 10.4.3

I've seen this on Wintel PCs too... sometimes right after a TP I'll fly very quickly pass sim crossings, and that'll get me in trouble. Things will disappear and may not load until I TP again, or if I relog.