It's not the mod my site works fine... It has to be something on their end. I am using VB 4.2 and using a custom theme that was updated for 4.2 same with all my website addons.... I would suspect there is something in their headers causing issues other then this mod... or another mod conflicting with it...
I would suspect the box script isn't being properly placed or they are using something in their web browsers that breaks it somehow?
Did you chmod the cache folder???
2) CHMOD directory "clientscript/steamprofile/cache" to 777
Here is an example page where you can see his mod works flawlessly
http://www.cozworld.com/showthread.php?t=4224
No editing on my part to anything just default settings of this mod...
And I am saying his mod works Flawlessly because there were issues before with the mod and with Steam and with my host GoDaddy! But all seems just fine for the last few months...
I would also be careful with complaining too much about his work as he is the only guy or one of two who gives a crap to make something for us/vbulletin for Steam for our websites!