thnx m8.
some additional info.
Windows 7 Professional
Intel (R) core(TM)2 Duo CPU
T7700@2.40GHz
RAM 2,00 GB
32-bit operating system
last update for Windows 7 (KB976264)
last security update for Microsoft Windows (KB978251)
no componets remote
firebird database Version 2.1.0 16780 Firebird 2. 1 Beta 2
run as a service, start automatically
we run also stereo tool, but the problem was there before