Roster export dropping leading zeros in the zip codes?  That is *not* a bug with Tendenci but, in fact, a default setting in Excel when opening a new worksheet.  The work around:

1. Run a roster export
2. Save it to your local drive (opening the file at this point will drop leading zeros
3. Launch the Excel application
4. On the menu go to "Data > Import External Data > Import Data
5. Browse to the file on your local PC and open
6. Choose Original data type radio button "Delimited" then next
7. For Delimiters select "Tab" and "Comma" then next
8. Select the column to define the data type (in this case we will select the "Zipcode" column and specify the data format to be "text"
   NOTE: you will have to scroll over to see all the columns
9. Then click "Finish"
10. Keep the default setting of "Existing Worksheet" and click OK.