I'm pleased to say that I've finally got my hover buttons working.
There may have been other contributing causes, such as my failure to
use File/Import rigorously, but the major reason was using the wrong
type of AU file.
It turns out that of all the attributes possible when creating an AU
file in GoldWave from the original MP3, only the 'Java/Web' type
works. Types that *do not* work include:
* 8 bit, mono, signed
* -law, mono
* A-law, mono
Presumably the stereo versions of those would fail too.
The first of those options is the default in GoldWave's drop-down box
when using the File>Batch Conversion feature, so naturally it was what
I used - particularly as I'd seen posts apparently recommending 8-bit
mono. When using just File>Save As, for a single AU file, there is no
attribute choice available. But, judging from the byte file size and
the fact that it works, that 'standard' AU appears to be the one with
'Java/Web' attributes (and it is also the smallest - and rather poor
This conflicts with recommendations I've seen elsewhere while
researching this issue. But FWIW, the above is the result of several
hours of testing.
The remaining flaw or feature I see here is that the hover buttons
*never* appear as anything other than grey rectangles in the Preview
window. I always have to use 'Preview in Browser'.
Terry, West Sussex, UK