FeedBurner not getting my latest blog articles from weblogs.asp.net–need help

This is more of an ‘I need help’ kind of an article. So, my feed stopped getting updated with my blogs – a few of my blogs from April and May do not show up in the feed.

Blog site: http://weblogs.asp.net/nmarun (duh!)
Blog RSS: http://weblogs.asp.net/nmarun/privaterss.aspx
Feedburner link: http://feeds.feedburner.com/nmarun

In the feedburner site when I click on the Troubleshootize link and go for a Resync, I get:

“Your feed filesize is larger than 512K. You need to reduce its size in order for FeedBurner to process it. Tips for controlling feed file size with Blogger can be found in Tech Tips on FeedBurner Forums, our support site.”

The help that feedburner points me to is to add the query parameter ‘max-results=x’ to the blog rss (….privaterss.aspx?max-results=10). This did not work for me.

I also activated Summary Burner allowing only 200 characters – again did not do the trick.

When I look at the results of the feed validator site, here’s what I see:

“Ensure lastBuildDate is present when slash:comments is used”.

This is where I’m stuck as to how could I possibly add the lastBuildDate element to the feed (or if I’m totally looking in the wrong direction).

Please help.