I may possibly, probably, in all likelihood be somewhat, maybe even entirely, responsible for this...
To clarify: I've gotten a PM from Trykon yesterday mentioning the same thing, only his message also presented the cause of the error as well. From said error message I can safely surmise that the site I had my flash siggy hosted on ended up blacklisted by whatever program is providing those errors and as such refuses you access as a result, unless you "understand the risks and proceed forward" or some other similar step I would assume.
I've already removed the flash link from my siggy but am not entirely certain that alone will fix all the threads / PMs I've posted in thus far.
Until a proper solution to deal with those can be found I can pretty much only assure you that the siggy I used was not bugged with any malware of any sorts and was merely guilty of being hosted in the wrong place. Thus if you have a choice to either block or unblock content from there whilst surfing on the VE pages you can do the latter as nothing will happen to your PC. Not sure about IE, but Firefox also seems to continue working fine for me, and I've since yesterday exchanged PMs with other individuals meaning that the issue itself isn't global.
Hope the above is found helpful in at least some small measure...
