php rss feed

I currently have about 5 wordpress blogs. I am not very proficient in php or coding, but have learned a lot through trial and error; changing themes, adding my affiliate banners, etc. I have always used the php include code from “rssfeedreader.com” to display rss feeds, and it’s worked without a problem until now. I have one blog, “doggy-training.com” that will not display the rss feed from ANY source, and I don’t know why.

I have tried a couple of rss plugins, but they don’t work right either. I’d really like to keep the simplicity of just adding the rssfeedreader code for my rss. Any idea why it stopped working on that site, and what I might do to get it back? Still works on all my others.

Thanks
Kay