She's been on vocal rest for the past few weeks, but Sugarland's Jennifer Nettles has plenty to say when it comes to the unfavorable comments some fans posted on message boards after learning that Sugarland had to cancel a few shows. The singer, who was under doctor's orders to take a break from performing to heal her strained vocal cords, admits she was both comforted and disappointed by some of the comments.

"I am never surprised as to the capacity of human beings to be wildly compassionate and loving -- nor completely and totally disrespectful and idiotic," Jennifer tells Music City TV, adding, "I understand people get disappointed and they love us and they love what we do. And they love what we do so much that they wish we were robots and could do it every second of every day and never have a cold or anything like that."

Jennifer's vocal problems flared up during recording sessions with singing partner Kristian Bush, causing the duo to cancel dates on Kenny Chesney's Sun City Carnival tour, including one in San Francisco -- a cancellation many fans were not aware of until they reached the admission gates. Kenny himself was annoyed with the outcry, saying, "It was really sad to see the way some people reacted to Jennifer needing to cancel her appearance in San Francisco ... we should all be concerned about her long-term vocal health more than any single show that she may not be able to do."

"It's very scary," Jennifer tells CMT Insider. "Because you think, 'All right, I can go out there - and I can do tomorrow -- but I may not do the rest of the year if I do tomorrow.' And that is terrifying. And that is when you say, 'Wait a minute. Let's pull back.'"

Sugarland returned to the concert stage last Thursday (July 30) in Bend, Ore. You can watch the superstar duo live in concert tonight (Aug. 3) at 8:00 PM ET on their ABC television special, 'Live on the Inside.'