adsense not loading <-- ads banner with error message

Lightspark plug-in informs me that there's a yet unsupported flash file bringing me the option to copy the error to the clipboard.

Here is the ressult:

"startIndex==0 /build/buildd/lightspark-0.4.6.1/scripting/toplevel.cpp:2879"

My system is a Pentium4 nettop ->Ubuntu 11.04 installed(and updated) just now using firefox with the official "lightspark flash integration plugin" (if I remember) in its repository.
Website with errors is not concrete one, due to it appears in a adsense banner.
website where occurs in my first time is "http://www.robotstxt.org/orig.html"(concretly in the header), but it succeed (as I can just see) in many others sites, included my own website, and it only occurs in an adsense block load, even if is a text block.
Is there a real bug or it's just an yet unimplemented function?
PS: Yes, my computer is s old, and yes, HD-video here is a mission:impossible, but I'm a web-master and I need web-browser working OK(my truly development computer has burned yesterday mysteriously... [core2 T5500])