Hi. I read your reply with great interest because I seem to be getting similar results to you.
As an initial test, I took a small folder of low res images pulled from an old web site :
TViX did not show any icons at all but was able to view the either in slideshow or individually.
Second test took a folder of 4 camera images (taken by my sister, so totally free from any edits etc by me:
TViX showed icons for 3 of the 4 images. I have examined them with IrfanView info plugin and can see no fundamental difference between the 1 'bad' and 3 'good' photos. Since bit depth, DPI, compression etc were all the same, I resized the bad image (keeping all other factors the same) and TViX still refused to show the new image as a thumbnail
As for creating thumbnail.tvix, I had no problem creating a dummy file with Notepad and naming it as thumbnail.tvix
To do this, I open Notepad and create a new blank file. When naming it, I enclose thumnail.tvix within quotation marks, e.g.
This forces any program to ignore the default extension for the file and name it with the name inside the quotation marks.
Did you remember to do this, or are your files actually called thumbnail.tvix.txt?
NOTE: Once I had created the first thumbnail.tvix, I was able to copy it to the next folder without any problem.
P.S. I am using FW 1.5.16
I remain at a loss to understand why some of the images are not being displayed as thumbnails. I am certain that this was not the case when I made my earlier replies in this thread.