If a BES client is logging alot and it has the roll the .bkg file more than once, it appears to be deleting the .bkg files so there is only one occurrence of them and not all the .bkg files for that day.
The client will make one and only one BKG file, generally because a single day shouldn’t pass the size of a normal file and we presume any “failure” was in that section. You can increase the sizes that the client considers a normal log file if needed.
I might submit a RFE for that because we have some small use cases where we patch Linux with hundreds of fixlets that causes the bkg to be overwritten. Increasing the log file size is a work around but it seems more drastic then to just allow the bkg to roll when needed.