Help defining range for macro comparing values in 2 columns and worksheets

[4lysaabri]

Hi, hoping someone can help me. I have an excel workbook with 2 worksheets, 'Source' and 'Master'. When a command button is clicked on the Master worksheet, a macro is run to compare the values in 2 specific columns on the 2 worksheets and paste any values that is not in column 'A' on the Source worksheet in the next available row in column 'D' on the Master worksheet along with the associated data in that row from columns 'B', 'C' and 'D' on the source worksheet. (rows A, B and C on the master remain blank). Right now, only 2 of the values from the source worksheet is being copied to column D on the master worksheet. The values missing from the master worksheet are in red on the source sheet...so this is what I would expect would be copied to the master worksheet. If someone can let me know why the entire range of column A on the source sheet is not being taken into consideration for the compare, I'd appreciate it. I've attached a sample of the workbook which has the code I'm using for review. Thanks in advance.