You can stop guessing, the redirects are likely the reason why your pages dropped from search results. How were the redirects set up. Were 301 redirects used? 302 redirects? This could make a difference in the outcome.

I know from experience that trying to fix the problem before you know the extent of the damage can be a bad idea. I know how difficult it is to wait, but that's what I would do for now.

Here are some non-evasive things you can do that could help.

• Make certain these corrections are present in your sitemap, .htaccess, etc.
• Clear your site cache
• You say you have "re-indexed" the pages you are concerned about. I would request a complete site crawl from all major search engines.