We have removed the limitation on Google Spreadsheet names, and simplified how we access your spreadsheets using the standard OAuth access protocol.
To upload a spreadsheet, use the Additions->Add (Upload) Multiple Markers menu item on your map, and select the Google Spreadsheets option. In the resulting dialog, click on the Fetch My Spreadsheets button to get a list of your current speeadsheets in Google.
You will have to grant ZeeMaps access to your spreadsheets. We ask for permission to access your spreadsheets now, and in the future, in case you want ZeeMaps to periodically update your map as the spreadsheet changes. You can revoke this right, at any time. Note that for the periodic updates to work, you must not change the header row of your spreadsheet.
Once you have selected the spreadsheet to use, ZeeMaps asks you to confirm the column headings to fields on the map. At this time you can also check the option to periodically update the map from the spreadsheet.
After you have confirmed the mappings, your data should get mapped. For small speeadsheets, it should get done in minutes or seconds. For larger spreadsheets (more than thousand or so entries) it can take a an hour or so. You will be notified by email when your data is uploaded. Alternatively, you can check your map in a little while to see how many rows were marked.