Change in Yahoo and MSN

Hi,

Does anyone know why it seems like every Friday, Yahoo and MSN seems to change their listing.

It seems every Friday, my site rankings disappear or goes down. Then over the weekend my traffic is very low.

Then on about Monday or Tuesday, the listings get back to where they were before. It happened today (Friday) too, I just hope my listings come back up this time too.

I am not sure why this happens but if anyone knows, pleaset let me know.

Thanks in advance.

I heard someone mention a similar scenario on another site. I think they came to the conclusion that Yahoo is possibly using old Google results during the weekend while they work on some things. Search during the weekend and see if your Google results are the same as Yahoo.

Well I know for a fact that MSN refreshes its index every few days so you can see up and downs. Yahoo, I am not sure though. They still may be testing different things.