SQL Compact 3.5 database - winforms app is trying to open database as read-only on 64bit machine

I have a simple winforms app (c# .net 4.0) that reads from and updates data to a sql server compact 3.5 database.

In my testing, the app is able to update the data in the database on bot my win7 32bit dev machine and on my windows server 2008 R2 64bit machine.

My client is able to read data from the database but when he tries to update or write new data, the app raises an unhandled exception:

"Opening a database as read-only requires a temp path to be specified. [Db name = MyDB.sdf]"

The client is logged in as Administrator and has full control permissions on the folder containing the .sdf file.

The client has tried copying the application (including the database file) to a number of different folders (temp folder, root of c:\ etc) on the machine, but 开发者_如何学编程it doesn't work anywhere.

The app works fine on the the client's windows 7 32bit laptop.

Any ideas on what could be causing this?

The client had to install SP2 for SQL Server Compact to get it to work correctly.

SP2 for SQL Server Compact 3.5

On a 64bit machine, you need to install both x86 and x64 versions that are contained in the self-extracting file from the download.