Looping and thread completion

Here's the gist of my package:

Get rows to process
Start loop
Get next row of data
- Generate Excel file? Generate Excel file.
- Generate RTF file? Generate RTF file.
- Generate XML file? Generate XML file.
End Loop

My package is bombing in random places, and I think it's because the
loop is going to the next row before the previous file generation is
complete.. How can I make sure that all threads for the current loop
are complete before allowing the loop to increment and start on the
next row of data? I'm at a loss. Any help would be greatly
appreciated. Thanks. - Mike