I recently re-built my development machine which now uses windows 7. On this new machine, VS 2010 can no longer open sln files directly from SS 2005. These are valid 2010 solutions (orginally created witih VS 2010) that worked fine until I re-built my machine. My co-workers have the same setup and do not have this problem.
The message I get is "The selected file is not a valid solution file".
I've re-built many times and used many installs of VS and never had a problem opening sln's from SS using VS 05, 08 or 10. I've just never seen this before. My co-workers have not had this problem either
I have re-installed SS 2005 as well as the latest SS update but nothing works.
VS 2010 can open solutions from the file system just fine, so it must be a SS thing.
Any ideas?
Edit for contents of Solution file:
Microsoft Visual Studio Solution File, Format Version 11.00
# Visual Studio 2010
Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "MyProject", "MyProjectX\MyProject.csproj", "{8E519F6C-A405-43AB-ADA0-F4829ECBEFE0}"
EndProject
Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "MyProject_BL", "MyProject_BLMyProject_BL.csproj", "{595FFFB2-5CC3-40BB-9059-32ACFAA9DEFA}"
EndProject
Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "LinqKit", "LINQKit\LinqKit.csproj", "{AEC98F52-83F5-488D-99EF-8AFFE7C9F6E6}"
EndProject
Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "MyProject_DL", "MyProject_DL\MyProject_DL.csproj", "{55506B29-70A8-4556-ADF9-2553B0F18379}"
EndProject
Global
    GlobalSection(SourceCodeControl) = preSolution
        SccNumberOfProjects = 5
        SccLocalPath0 = .
        SccProjectUniqueName1 = MyProject\\MyProject.csproj
        SccProjectName1 = \u0022$/MyProject.root/MyProject/MyProject\u0022,\u0020
        SccLocalPath1 = MyProject
        SccProjectUniqueName2 = MyProject_BL\\MyProject_BL.csproj
        SccProjectName2 = \u0022$/MyProject.root/MyProject/MyProject_BL\u0022,\u0020
        SccLocalPath2 = MyProject_BL
        SccProjectUniqueName3 = LINQKit\\LinqKit.csproj
        SccProjectName3 = \u0022$/MyProject.root/MyProject/LINQKit\u0022,\u0020
        SccLocalPath3 = LINQKit
        SccProjectUniqueName4 = MyProject_DL\\MyProject_DL.csproj
        SccProjectName4 = \u0022$/MyProject.root/MyProject/MyProject_DL\u0022,\u0020JNAAAAAA
        SccLocalPath4 = MyProject_DL
    EndGlobalSection
    GlobalSection(SolutionConfigurationPlatforms) = preSolution
        Debug|Any CPU = Debug|Any CPU
        Release|Any CPU = Release|Any CPU
    EndGlobalSection
    GlobalSection(ProjectConfigurationPlatforms) = postSolution
        {8E519F6C-A405-43AB-ADA0-F4829ECBEFE0}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
        {8E519F6C-A405-43AB-ADA0-F4829ECBEFE0}.Debug|Any CPU.Build.0 = Debug|Any CPU
        {8E519F6C-A405-43AB-ADA0-F4829ECBEFE0}.Release|Any CPU.ActiveCfg = Release|Any CPU
        {8E519F6C-A405-43AB-ADA0-F4829ECBEFE0}.Release|Any CPU.Build.0 = Release|Any CPU
        {595FFFB2-5CC3-40BB-9059-32ACFAA9DEFA}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
        {595FFFB2-5CC3-40BB-9059-32ACFAA9DEFA}.Debug|Any CPU.Build.0 = Debug|Any CPU
        {595FFFB2-5CC3-40BB-9059-32ACFAA9DEFA}.Release|Any CPU.ActiveCfg = Release|Any CPU
        {595FFFB2-5CC3-40BB-9059-32ACFAA9DEFA}.Release|Any CPU.Build.0 = Release|Any CPU
        {AEC98F52-83F5-488D-99EF-8AFFE7C9F6E6}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
        {AEC98F52-83F5-488D-99EF-8AFFE7C9F6E6}.Debug|Any CPU.Build.0 = Debug|Any CPU
        {AEC98F52-83F5-488D-99EF-8AFFE7C9F6E6}.Release|Any CPU.ActiveCfg = Release|Any CPU
        {AEC98F52-83F5-488D-99EF-8AFFE7C9F6E6}.Release|Any CPU.Build.0 = Release|Any CPU
        {55506B29-70A8-4556-ADF9-2553B0F18379}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
        {55506B29-70A8-4556-ADF9-2553B0F18379}.Debug|Any CPU.Build.0 = Debug|Any CPU
        {55506B29-70A8-4556-ADF9-2553B0F18379}.Release|Any CPU.ActiveCfg = Release|Any CPU
        {55506B29-70A8-4556-ADF9-2553B0F18379}.Release|Any CPU.Build.0 = Release|Any CPU
    EndGlobalSection
    GlobalSection(SolutionProperties) = preSolution
        HideSolutionNode = FALSE
    EndGlobalSection
EndGlobal
Actions taken:
Step 1: File -> Open Project/Solution

Step 2:
Select SourceSafe on left menu. You can now see ss_IssueTrak database stored in sourcesafe

Step 3:
Navigate to Solution IssueTrakX.sln

Step 4:
Click Open or double click IssueTrakX.sln and receive this error

 
                        
In Visual Studio File>Project from Existing Code, then navigate to the Root folder containing the .sln and add all of it's contents to your new project. Everything should load in your new solution.