There were some problems using BibTeX on Win32 because of a wrong path usage
in the TeX \bibliography-entries. This has been fixed and proofed now!
The new binary version (called version: '1.1.5a (Win32)') is availbale under
http://www.fh-hannover.de/mbau/tim/hentschel/lyx/index.htm
as usual! There the single executable lyx.exe to replace is available, too!
Claus
