popup alert on use with lightbox2 : No width/height set for items. This will cause an infinite loop. Aborting...

Hi,
I call some nodes in a lightframe using the lightbox2 module.
A jcarousel is present in those nodes and works pefectly in a html page but when the node is called by the lightbox2 module and the modal windows happens, an alert happens two time :
jCarousel: No width/height set for items. This will cause an infinite loop. Aborting...
If i click the ok button on each time, the third time is ok.

My width and height css items proprierties are set.

I comment the lines 556 to 559 in the jcarousel/jcarousel/lib/jquery.jcarousel.js where the check on the dimension definition is done : the alert disapear but it's very tricky.

var d = this.dimension(e);
/* if (d == 0) {
                    alert('jCarousel: No width/height set for items. This will cause an infinite loop. Aborting...');
                    return 0;
                } */

I checked the "d" variable in the firebug console after i have commented this line in adding this line :

console.log(d);

So when the lightframe is loading the d variable take this value :
0
0
250 (it's the css setting width for my items)

Any idea where the problem is ? probably in interaction between jcarousel and lightbox2 but where...

Thanks

Timos