I too just discovered that paychecks are not always posting to Projects. We pay weekly and on the Project screen, the 10/20 payroll posted just fine into the Time Activity AND the Project Transactions AND the Salaries Expense Total (Overview screen). However, the 10/27 and 11/03 did not post to the Project Transactions or the Salaries Expense Total (Project Overview screen). The time posts to the Time Activity tab on the Project just fine. 

Any resolution as to why this is occurring?