I tried and tried.....and tried some more to get Feedflares from Feedburner to work on my Blogger blog. I search all of the help groups and forums on both Blogger and Feedburner - and sent the little bX xxxxx message (can't remember what the numbers were) to the Blogger Resource.
Every time I would try to get it to save I would either get an error message about 'parse' and 'script' OR it would simply not save and give me the bX error message.
Finally, I sat down and thought about it ~ and, of course, I was using IE 7 on Vista - if there's a problem, always try another browser. I went into my blog using Firefox, copied and pasted the code, hit save and wah-lah! Feedflares work!
So, just go into Feedburner and set your feed up - click 'Monetize' and click to enable Adsense (you have to be signed up with Adsense and have it set up to allow Feedburner). Click 'activate' at the bottom and then click the link for setting up what blog you're using. Chose 'Blogger' and copy the code Feedburner gives you ~ follow their instructions to paste the code into your blog ~ but use Firefox as your browser when you're doing this and it should work the first time!