Pages drop one day after submitting to Sitemaps program

[spinweb]

My site had 72 pages consistently in Google's index. When I checked today, my site was down to 43 indexed pages. Unfortunately of the pages they dropped, two of them were ranking well.

I don't know if it is a coincidence or not, but we entered the site yesterday in the Google Site Map program and uploaded an xml site map file with all the main pages listed (about 65-70 pages). The cache shows the Home Page was spidered 2 days ago, so I don't know if this is related to submittal into the Google Site Maps program yesterday (5/16).

I emailed Google about this and received the canned response and links which didn't answer my question. Has this happened to anyone else and what steps did you take to increase your indexed pages to the where they were previously? Or at the very least we need to get the two high ranking pages back in the Google index. Also, is this related to placing the site in Google Site Maps? Thanks for your help.

[edited by: tedster at 3:22 pm (utc) on May 17, 2006]
[edit reason] fix formatting [/edit]