As this question is rather old but still is marked as "unanswered" I take the liberty to post an answer this late which I hope not only you will benefit from but all other webmasters/SEOs with similar issues.

First of all: Duplicate pages and therefrom duplicate title-tags etc. are of course meant to be taken serious but there are no easy fixes in my opinion and especially not if your design and database set-up is causing large amounts of duplicated content.

But is it a big problem Google-wise? I have my doubts based on conflicting signs and indications given by Google Webmaster Tools and the SERPs in general.

An example I just dug up for you: One of the big players in the field of recipes (allrecipes.com) has +5.000 search results indexed by Google ALL with duplicate title-tags which would bring up all the red flags in the Dashboard.

But based on Googles trends for searches, allrecipes.com are still outperforming their closest competitors. Their search result-urls are unique but all have the same title-tag...so +5.000 duplicate title-tags is probably not really a problem in their perspective.

What to do then?

All though your website seems to have been designed with quite a few potential problems built into its core I would personally hesitate spending a lot of resources on fixing it, especially if your traffic from Google is not taking a bashing.

Eventually your website will be in need for a design re-do and perhaps a change of content management system/database system.

Plan ahead and make sure that you will be able to control this issue in your next version.

It could f. i. be by having all search results appear more like individual pages with individual urls. With a little bit of effort you could make each search result unique with unique title tag and url and thereby bring more traffic to your site.

Best of luck with your efforts

Jens Peter