crawl errors

Hello,

I am getting Google crawl 404 errors for the blog post urls.
Some query string gets appended to the actual urls and a 404-page not found error occurs.
For example, a valid url : http:///www.mydomain.com/blog/tag/categorySlugName/
Extra query string appended : http:///www.mydomain.com/blog/tag/categorySlugName/&/page/3/http://itunes.apple.com/us/app/appname/id1234/page/4/%3Chttp://itunes.apple.com/us/app/appname/id1234
I cannot figure out how these query strings get appended to the valid url. It is not present in the hyper links within the blog.
More info : Permalink is set to month and date.
The query sting parameters are unique always. A 301 redirection is too much to handle because these crawl errors increase day by day.
Please help solve this.