Duplicate Meta Descriptions

[rrw]

After submitting my sitemap to Google, I'm looking over my content analysis. It tells me that I have 655 pages with duplicate meta descriptions, and 906 with duplicate title tags. I understand the tags, and I can fix them, but the meta descriptions has me stumped. My questions:

1) Almost all of the duplicate meta descriptions are for the same product, but for some reason they show up as the product page, and as the product page with the review box. For instance, one says that these 2 items have duplicate meta descriptions:

Product_A_p_17534-reviews.html
Product_A_p_2098-321.html

I only have 1 Product A, so I'm not sure why it is finding 2 pages for this product. The pages above are identical, except the first page has the box at the bottom for the customer to input a review.

2) Some of the duplicate meta descriptions are for the same identical product that is listed in 2 different categories. For instance:

Product_B_p_12939-1706.html
Product_B_p_12941-1706.html

Now both of these are identical (again, I only have 1 Product B), but these 2 pages refer to 2 different categories on which the product is offered. For instance, category "Blue Widgets", and category "Show All Widgets".

Unfortunately, since I submitted my sitemap my organic ranking on my number one search term dropped from 3rd to 10th place, so I really need to fix these issues.

Any help is greatly appreciated!

[Mark]

yes,
I've heard of issues where sitemaps don't really improve your SEO

I think I will remove mine.

And, is there a way to edit the robots.txt file to prevent the review pages from becoming duplicates? I know for a fact that Google will penalize you for duplicate content.