The point from the previous post is worth checking out but the original error message does contain the line :

2008-06-13 08:45:15.78 *** Error: This log cannot be restored because a gap in the log chain was created. Use more recent data backups to bridge the gap.

RESTORE LOG is terminating abnormally.(.Net SqlClient Data Provider) ***

suggesting there are transactions missing.

also, thinking about it, jjsilva, I note your out of synch' threshold is set at 45 mins, so if you do not do a restore for an hour you will get these Messages, so its not really an error just a warning you can ignore with regard to the test u did in the afternoon