RSS Feed Error

I think the last update 4.1.1 seems to have messed up my feed.
When I click on my feed at https://feeds.feedburner.com/MomsWearYourTeesBlog
I get the following message
“This page contains the following errors:

error on line 289 at column 187: Input is not proper UTF-8, indicate encoding !
Bytes: 0x03 0x3C 0x73 0x74″

I am not sure what is causing the problem or how to fix it!
Thanks for any help!