Combing CSV files in dataflow and dataflow does not refresh and grab new csv files.

I have a dataflow that I want to go in to a sharepoint folder and combine all of the csv files in that folder. Each day a new file is automatically added to that folder. I created a dataflow, but the problem is when I refresh the dataflow the number of csv's that it combines is static. So whatever csv files were in the folder when I created the dataflow is what it refreshes. It does not find new csv files. This is the code I am using:

 

Any ideas why it won't pick up a new csv file the next day when it moves into that folder?