barcode font - almost perfect, but . . .

I tried to create a Code39 bar code font but it did not work properly
What have I done?

I generated BMP-Files 500x500 pixels containing one glyph each.
I imported these images an let it trace
I saved the file as a TTF.

What did work?

All the characters and the figures are working OK
In terms of symbols the * . $ and % are working well.

What did not work?

The symbols = / and + are coded well (double checked it twice) but they generate the characters ß - and \ (i.e. I coded a = and it came out as a ß-Character, a / comes as a - and a + comes as a )
Instead of the blank that has a barcode in code39 there is only a blank space with not bars, although the barcode pattern is shown in the Editor.

What have I done wrong?

more info and all the files I used for downloading at http://www.gunnis.de/fonts/

Try the test feature (Font → Test) inside the Font Creator Program.
When the test window shows your font as expected, you might need to restart your computer.