Google XML Sitemaps tag pages issue

I’ve turned up my memory on this to 36m and am trying to process my sitemap to include my tag pages but when I click on rebuild it crashes everytime. My site has about 1600 posts or so which means it’s not like 100,000 pages of tags. When I don’t select the tag pages it processes properly..i’d like to include my tag pages in my sitemap but can’t seem to find a way around this. Your help is appreciated.