I have a site with verry high competition which is ranking top 10 for verry competitive keywords.

I used to receive a lot of traffic from MSN, but a month ago my index page was no mre indexed ( my other pages were there ). After 4 days the index page was back receiving visitors. After 4-5 days again was no more in index. This is happening for 1 month, and i don;t know what is happening.

First i thinked was a problem with my host. I speacked to them and they told me that their server were not down on that periods.

Can anyone tell me what is happening?

No, It's been happening for alot of keywords.

I'm not really so concerned but I don't have competative keywords.

Probably just some updating going on at MSN. Chances are it's nothing to worry about. Give it a few more days and see if everything gets sorted out. It's pretty common with all the search engines to see your results bounce all over the place for a few days and then settle back down.

The problem is that is a search on MSN for www.domain.com i cand find my home page ( http://www.domain.com/ ) but i can't find the other pages of the site.

It's not about the keywords.
Like my home page adress is deleted from their index every 4 days and then is putted back.

Try site:www.yourdomain.com to see what pages they have indexed. Could you post a link to the site in question? It might make it easier to figure out what's going on.

I can't post the link. Sorry.

I know how to search for all the pages of the site which are indexed.

MSN is showing me all the pages but the index page ( www.domain.com ) is not indexed.

That is kind of strange. I'm not sure why they would be dropping the home page, but always keeping the others. Can the page be found without the www?

Just curious about why you can't post the link. It's obviously something that you want people to know about since your main concern is that you're not coming up in MSN searches. Or is it against forum rules to post the specific link? Sorry if I'm too curious.

happens a lot, nothing you can change, don't worry about it.

Ok.
But my site is ranking well. And is happening many times and is affecting me.
Can i know what is the reason?

I don't think we can give you any more reason than we have. Search engines update their algorithms and their servers and when they do results bounce around for awhile until they eventually stabilize again. It's a very common and there's nothing you can do to change it. I don't think anyone outside of employees at MSN could tell you what they're doing now or why it's affecting your results.

The only way I could give you any more information would be if I could look at the page in question and see if I notice anything in the code that could be causing what you're seeing or just do some general research about the domain at MSN.