{{Quickfixn}} Error on synching messages: 58=MsgSeqNum too low, expecting 279 but received 9

[Manuel Lopez]

This is likely some issue with my setting, but I'm trying to figure
out how to deal with out of synch messages.  The error is:
58=MsgSeqNum too low, expecting 279 but received 9
Or is this something I should be handling in code?  Any pointers are
appreciated--I may easily have overlooked something obvious.  Thanks.

My counterparty says:
"Do not use 141=Y on your session.  It is important that sequence
numbers are ONLY reset at the end of each trading day.  In the event
of a disconnection our FIX engines can recover any missed messages on
reconnect.  Always send a logout message when you cleanly disconnect
your application. This allows us to shutdown your session cleanly and
identify that you have logged out in a normal manner. If you
disconnect without sending a logout, we will assume you have
disconnected abnormally and that there is a problem."

Here is my config file:

# default settings for sessions
[DEFAULT]
PersistMessages=Y
FileStorePath=msgs
FileLogPath=logs
ConnectionType=initiator
UseLocalTime=Y
StartTime=18:00:00
EndTime=16:59:00

# session definition
[SESSION]
BeginString=FIX.4.4
SenderCompID=myID
TargetCompID=theirID
ReconnectInterval=30
HeartBtInt=60
LogonTimeout=10
LogoffTimeout=10
SocketConnectPort=n
SocketConnectHost=n.n.n.n
MillisecondsInTimeStamp=N
ResetOnLogout=N
ResetOnDisconnect=N
RefreshOnLogon=Y
EnableLastMsgSeqNumProcessed=N
MaxMessagesInResendRequest=0
SendLogoutBeforeDisconnectFromTimeout=Y
IgnorePossDupResendRequests=N
ValidateFieldsOutOfOrder=Y
ValidateFieldsHaveValues=Y
ValidateUserDefinedFields=Y
RequiresOrigSendingTime=Y
UseDataDictionary=Y
DataDictionary=spec/fix/FIX44.xml