A colleague recently approached me to ask why they couldn't save the survey results from one of their external SharePoint 2010/hosted sites. So, I did some digging...
Scenario:
You attempt to use the 'Export to Spreadsheet' option from your SharePoint survey Actions toolbar:
When prompted to open or save the IQY file, you click either Save or Open - let's assume you choose the 'open' option for now. Excel fires up and then you receive the error dialog which tells you that you don't have adequate permissions to modify this list (you receive the same error if you save the IQY file locally and then attempt to open it):
Your initial thoughts tell you that the error has something to do with either the Office client version currently installed - perhaps it's incompatible with the current version of SharePoint - OR it has something to do with the current mode of authentication - OR client integration features in SharePoint (either in the permission level or in the current list or library) are disabled; OR your user account has insufficient permissions.
To troubleshoot, you verify that (1) client integration features are indeed enabled and that you have full rights to the site/list; (2) you receive the same error in both Office 2007 and Office 2010; (3) you check the authentication method currently being used - BINGO! The server is configured with BASIC!
My colleague needed the results now, so - a quick and dirty fix... I saved the survey as a list template (.STP) with content and then imported it into one of my dev environments configured with NTLM; created a new list from the template and successfully exported the data out to Excel.