UTR: Error with Spi-V OSX app loading some GIF

I have recently build some Spi-V pano that are similar to some I made one year ago and encounter problems when I load these panos in Spi-V application 1.4.2 for OSX.

At launch time, I get a "Director Player Error, Three parameters expected, Script Error, Continue ? No Yes".

It appears to be linked with some new GIF I made in Fireworks with very similar method to other that just works OK.

Panos are working OK in Win Spi-V app with Showkwave 10.2

The error occurs with Shockwave 10.1.1r16 on OSX PPC. I don't encounter it if I place projector resources and xtras from my Director 10.1 app.

Before I investigate further, has anybody encountered this ?