Simon,
This is interesting since there was no specific support for Panasonic/Leica .RAW RAW files in 4.4.3.3. We actually added basic support for these in 4.5.
I suspect you are probably using a Mac, and the files probably have the Mac type set to 'TIFF' despite the .RAW filename extension?
In 4.5, we no longer pay attention to the Mac type since this was causing problems (because the Mac type was either wrong or there was no filename extension whatsoever). The Mac version behaves more like the Windows version (and MacOS) in that we require files to have an extension and we use that extension to determine the type of file.
If your files were "recognized" in 4.4.3.3 it was only because they were paired with JPEGs shot in RAW + JPEG mode. The .RAW files by themselves (if on Mac and with a 'TIFF' Mac type) would not show any thumbnail since Panasonic's RAW format doesn't embed any type of preview (JPEG or TIFF thumbnail).
These files are supposedly the same as the Leica D-LUX2, but I will contact you privately about uploading a sample photo from the DMC-LX1 (and if it is from the Mac I will ask you make a Stuffit archive in order to preserve the Mac type/creator).
--dennis
