No solutions for you, but I have had this issue also... actually my wife has on her account... I'm doing some testing on my account... she said, she "thought" is she manually saved the message after she started, that it didn't happen again... but wasn't for sure....
If I have any luck finding a work around or find a setting I have wrong, I'll post it here.
Also might check your error file in the log folder, although I didn't see anything in mine for today, when she got the last error