I've been having some issues getting my VPC updated to SQL Server 2008 RC0 and Visual Studio 2008 SP1 Beta so I can record a couple screencasts on using Virtual Earth with SQL Server 2008.  I swear I read through the readme docs:).  However, I could not get Visual Studio 2008 SP1 to install.  I'm in the process of building a new VPC.  I probably should have done this in the first place since my original VPC had so much beta software installed (including the SQL Server 2008 Feb CTP).  Before I tried to install either, I decided review the readme again and do some basic Internet searching before I started.  Turns out I should have searched around the first time.  There is a known issue related to the order in which you install the two.  I found the following entry in the forums:

http://forums.microsoft.com/msdn/ShowPost.aspx?PostID=3523799&SiteID=1

which states:

"SQL Server Compact installation fails when the products are installed in the following order:
1. Install SQL Server 2008 RC0
2. Then install Visual Studio 2008 SP1 Beta

The workaround for the issue is as given below:
1. Install SQL Server 2008 RC0
2. Go to the Add/Remove Programs
3. Uninstall SQL Server Compact 3.5 SP1 Query Tools Beta and SQL Server Compact 3.5 SP1 Beta
4. Install Visual Studio 2008 SP1 Beta
5. Install SQL Server Compact 3.5 SP1 Query Tools Beta (SSCESqlWbTools.msi) from the folder - Servers\Setup on the SQL Server 2008 RC0 installation media (CD/DVD/Layout)
6. Go to the Add/remove programs and verify that the following are installed:

a. SQL Server Compact 3.5 SP1 Query Tools Beta;

b. SQL Server Compact 3.5 SP1 Beta;

c. SQL Server Compact 3.5 SP1 Design Tools Beta

The reason for the failure is that SQL Server 2008 RC0 and Visual Studio 2008 SP1 Beta install the same version of SQL Server Compact 3.5 SP1 Beta MSI's. If SQL Server Compact is already installed on the machine SQL Server 2008 or Visual Studio 2008 SP1 Setup has to skip the installation. There was a bug in the Visual Studio Setup and it has been fixed. The fix will be available in the released version of Visual Studio 2008 SP1"

Hopefully this saves some headaches for anyone who is trying to install both on the same machine.

-Marc