Preview glyph alignment

I’ve created a font that’s all empty except 6 or so glyphs. When I was editing the last glyph I noticed that even though the shapes I created were close to the “origin” i.e. the two red guideline’s intersection, the preview pane showed this new glyph way over to the left, in fact over the top of the previous character. But when I use the font for real, the character is aligned OK. If I drag all the shapes to the right so that the preview is correct, the actual font (and the glyph overview) show the shapes way to the right. So it seems the preview is doing something wierd.
The glyph validator is happy with all the shapes etc.

I can email you the TTF if you like. The s/w verion is 5.0 (freshly downloaded)

Check that the glyph’s left side-bearings are zero, and that the characters have a suitable advance width. (Alter Enter = glyph properties). Or use tools autometrics to calculate suitable metrics for the font.

I used Tools Auto Metrics…SORTED ! Many thanks.