my checkbook doesn't balance in GP match my GL balance

hello all..

i'm facing a problem in my checkbook , there's a difference between

Sub-ledger and general ledger in banks module after we analysis

the difference we found that, there was a sales cash receipt already entered and posted

but I can’t find it on bank deposit window ( it's lost )

although it’s posted to General Ledger

so I need the reason behind this problem and how to solve ?

thanks