One by one:
In order to work, the bloom module absolutely needs DirectX9 to be completely up-to-date with the various updates from Microsoft.
And it is: I have installed the latest "refresh" runtimes, as I always do (I'm an update-freak!)

Also, the bloom will not work if the video card is too weak, or if it doesn't have enough video memory onboard,
As you can see from my signature, I have got a very strong video card with a current chipset and 1 GB of VRAM.

or if the AntiAliasing is set too high.
It's set to 4x, a value which I believe almost all flight simmers use.

So the reason must be something else. It could be the CPU, but in this case the problem is probably not the fact that it's single core or that it's fairly slow, because it appears that other users were/are using the bloom with a similar CPU. Perhaps an Athlon64-only problem?
Please consider also that I was getting the exact same problem with my old video card, an NVidia 6600GT; nothing has changed when I changed the card, the bloom still turns my sim into a beautiful frozen screenshot.
But first of all, the version I was using is older than the one on SimV, I'll try that and keep you posted about the outcome.
Thanks