I get this error almost every day on my Exchange 2003 incremental backup. The only thing descriptive that BE shows with this error is "The Exchange Store service is not responding. Backup set canceled. A communications failure has occurred." If I manually run the job when I get to work in the morning it finishes successfully. I even changed the time of the incr. backup in case something else was going on with Exch. at the time of the backup. Still no luck. Has anyone had this issue before and found a fix? The only thing I have done is restart EXCH and BE services. No luck.
BE 11d Rev. 7170
Hotfixes installed - 17 through 28
Exchange 2003 Version 6.5.7638.1