Kim, that might be because the zip spans both sides, I don't know. But with a little work you can fix it:
- Build a Viz with all possible marks visible
- Rt-Click the map somewhere away from any marks
- View data
- Click the upper left corner of the table to highlight the whole sheet (just like in Excel)
- Click copy
- Past this into an Excel file
- Delete the (generated) from both the Lats/Longs
- Connect to this worksheet with a live connection
- Build your viz again using the Lats/Longs that are NOT (generated).
- Now go to your Excel spreadsheet and start experimenting with the Lat for that particular mark (Don't forget to save the Excel file before hitting F5 in Tableau.)
It's hard to tell what you're zoom level is but I start with subtracting (or adding if you want it to go up) .05 or maybe .1
Hope this helps. BTW, if Tableau let you use the generated lat/long fields in a calculation, you wouldn't have to do any of this. Instead you could write a simple statement like this:
IF [Zip]="V7L" THEN [Latitude (generated)] + .05 ELSE [Latitude (generated)] END
But alas this is not possible.