Weird problem with Photo-Gallery

I used the fine photo-gallery tutorial on several Flash-websites and a weird problem is that some users with older computers (say a 400MHz Pentium) but fast connection (DSL) report that the pictures won’t load, the pics are about 10-20 KB, so they should, even with a slow connection load within 7-20 sec.
I have absolutely no idea why this happens.
For example I used it on this site:
[COLOR=Red]Link removed by claudio[/COLOR]
I used the code exactly as in the tutorial and with fast computers it works relly fine.
Any ideas?
Thanks in advance!