The last part of 10.5, all through 10.6 and now all through 10.7 (every point upgrade in-between all of them! there has been a problem which manifests itself as icons losing their snapshotted positions - not remembering where they are supposed to be between restarts. (Snapshotting is an Amiga term - so sorry for that.)
https://discussions.apple.com/thread/2326685?start=0&tstart=0 <-- from 2010 and even before to present day --->
(and I could go on and on with more links too)
There has been this very anoying problem among us. Sure there are user solutions like rm -f ~/Desktop/".DS_Store" + a finder kill or searching the system for ".DS_Store" with exact match filename and "is invisible" qualifiers and then trashing them... or even using funky 3rd party apps like OnyX. But some of us spend a lot of time setting up icons in groups or fitting them over a custom Desktop images (wall paper) and this faulty icon behavior is not tollerable. It should have been addressed years ago! My souped-up MacPro can't accept Mountain Lion so I duno if that's fixed it but the latest revision of Lion sure doesn't. A fresh install, an update to the latest revision, and it does it to me everytime.
The problems with .DS_Store in general are incredibly anoying and have been with us since since 10.4 that I know of. There's even a user here named "ds store" currently with 21,405 point-count probably from addressing the thousand of problems which ds_store has caused us over the years.
I'm here to beg and plead for a permanent fix for this problem in one final Lion update or system patch. If it's not been addressed in Mountain Lion then please, for goodness sake, fix it there as well. I've been a loyal paying user of Apple products for long enough that I feel qualified in asking for this.
Thank you very much for reading and if any users here feel similarly then please feel free to add your comments and suggestions below. Especially if you know of a modern easy fix to this problem.
Tesselator In Japan.