Finally... as suggested elsewhere for similar problem, I totally resumed firefox and reinstalled the plugin, now it works. Weird that the same behaviour occured on two different machines, isn't it? Thanks for your effort

@unknownuser said:

I assume it appears in the installed Add-ons Extensions list ?

yes

@unknownuser said:

By default it ought to appear in the bottom-right of the bottom Add-on bar [although later on you can relocate it using 'customize'].

nor I can find it among available commands to customize the bars

@unknownuser said:

Do you have any odd settings in Firefox Options regarding js etc ?

not that I know

I cannot see the icon, the extension had been correctly installed but there's nothing in the extension bar
Same issue both on win7 and XP, firefox is updated to vers.24.0

mmm... actually it seems that the insertion point of the imported model is its axes origin, so you've just to show axes and put it on the origin of the model with the scenes.

if only importing a model could place it at origin it would enough then override it.

I'll try to explain... let's say I've "model1.skp" with the scenes I would like to apply to "model2.skp". I could delete all the objects of "model1.skp" and import "model2.skp" inside it, then save as "model2.skp". The problem is that inserting the model requires a point to place it, so I need to define a reference origin before.
Or do you know a way to insert a model directly keeping the same global axes? (...that would need a discussion itself)

let's pretend you've never used SU before...

to know if a software runs well on your system before purchase it, you've just to use it for a trial period and see if it crashes

Me neither, I've installed it but still using version 8
Perhaps when I'll see some good native UV tool I might start using a new version

amazing ... also a bit frustrating considering my skills with blender

this plugin is spectacular ... how could I missed it?

https://copy.com/D3DVq8xwNPkg
I have these ones... some material might be duplicated in different folders
Note, they are not library files! Unpack and copy the folders directly under ..\Kerkythea Rendering System\MaterialEditor\Libraries

I have some wood floors if you like http://tridem.altervista.org/risorsekt.html
I believe most of the libraries can be reached also by the forum http://www.kerkythea.net/forum/viewtopic.php?f=19&t=6425

time to playing around... rendered with Thea

though, your map seems wrong since reliefs should correspond to white areas. Note that the material preview has a bug and works on the contrary way

A try with Kerkythea

I'm not able to reproduce the issue, this is a quick test I made and it seems ok

but as Solo said you've applied the material on the group (that usually is not a problem) and also on the backface of the tiles, try to clean the scene

it seems rather a UV issue, try applying cubic mapping in kerkythea

Congrats! to me this confirms that things are going the right way for sketchup