Are you regularly empty the Cache. There are difference reasons why you get the no data warning, but a corrupted Cache folder may do the job.
I agree that those warnings or alerts are a big nuisance, and, I wish that there would be a way to get what is there without repeated alerts, which accomplish nothing. My favorite is to be told that one of my account's server was not available. Once, I got the alert five times, about every 20-30 sec., until I, eventually, quit mail.
UserAgent: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.7.12) Gecko/20050915 Lightninghare/1.0.7
"I've got a very poor sense of direction. I keep forgetting which way is forwards."
WinXP, SP3, 512 MB, 3.0.15 regular, 3.5.5 regular and portable , TB2.0.0.23, Flock2.5.2, IE8.0, SM2.0, Google Chrome2.0.x, Zone Alarm Firewall; AVG9.0, JRE1.6_17