De-indexed by MSN?

[Titor]

Greetings!

Recently I had a few problems with a few sites I just start to handle (all on same IP):
www[dot]pmoz[dot]org
www[dot]pro-board[dot]com
www[dot]jdhealthcare[dot]com
Recently they got de-indexed by MSN, for a reason that remains wierd to me. Even more a few other sites that linked to these ones (located on different IPs) received a penalty (drop in SERPS).

Do you have any idea why this happend - as far as I know the sites are legitim and no black hat seo is used.

Please let me know if you notice anything that may result in this MSN ban / penalty.

Thank you in advance.

[Guest]

In late December last year I discovered that my traffic suddenly dropped just to totally disappear in January. This happened to all sites that I have on the same IP address.
I thought it was a 301 redirect that was the problem and/or the translation software I used but MSNDude said that that wasn't the case.
I was told that it was my link exchange that was the problem and he pointed out one site that he said I was using "on-page spam technique" and asked " if I was doing this for SE's or for my visitors"
I have checked that site and been tring to figure out WTH "on-page spam technique" is but stilll can't figure it out. I have changed a lot on that site but MSN/Live still won't index the site.
A VERY interesting thing is that I pointed out several sites that are banned to him and he said one of the sites "seemed fine" and was going to be re-included, which leads me to believe that if you have sites on the same IP address they all get banned if one site is dubious to them. To me that is like you punish everyone in a family if one family member is bad. Doesn't make any sense if you ask me!