Search Alerts are not working in MOSS 2007?

I have tried lot with Search alert in subsites and site collection level.
I checked all this point which is given in this blogs.
http://blogs.technet.com/victorbutuza/archive/2009/02/24/search-based-alerts.aspx
But still no alert E-mail.

Then, I found that we have to create search alerts on the root site collection: http://servername
What I did,
- created search center underneath rootsite collection. http://servername/searchcenter
- redirect the search result page on new searchcenter page (/searchcenter)

Then i tried to test alert on my account.
Done. Finally i got search alert E-mail regarding item change, created as a daily or weekly report.

Thanks,