Most users after migrating Mac OS X from 10.5 (Leopard) to 10.6 (Snow leopard) reports about application crash during saving files. Particularly with Adobe Photoshope CS3 and 4, also with MS Office applications. After investigating this issue , has been found that it coursed by errors in Spotlight mechanism. So, until Adobe and Apple works to solve this problem there is an ultimate solution.
Sympthoms of the problem: when saving files (e.g. in Photoshop CS4) , application crashes with error message. All changes lost.
Solution: Make a new user account and transfer all files and settings there. Now everything will work fine!
Looks like only users who previously migrated from Tiger to Leopard now got this problem. Most of users who installed Leopard from scratch have no such problem whatsoever !