Проблема с символами - может ' t шаг в код .NET

Я не могу заставить Visual Studio 2010 SP1 перейти на какой-либо класс .NET Framework, я нашел много руководств в Интернете, но ни одно из них не работает ...

Вот что говорит окно вывода:

Step into: Stepping over method without symbols 'System.Collections.Generic.SortedSet<Shared.Optimization.Solution<GaTest.CurveFitSimplex,double>>.Remove'

Вот все содержимое окна вывода:

'GaTest.vshost.exe' (Managed (v4.0.30319)): Loaded 'C:\Windows\Microsoft.Net\assembly\GAC_32\mscorlib\v4.0_4.0.0.0__b77a5c561934e089\mscorlib.dll', Symbols loaded.
'GaTest.vshost.exe' (Managed (v4.0.30319)): Loaded 'C:\Windows\assembly\GAC_MSIL\Microsoft.VisualStudio.HostingProcess.Utilities\10.0.0.0__b03f5f7f11d50a3a\Microsoft.VisualStudio.HostingProcess.Utilities.dll', Symbols loaded.
'GaTest.vshost.exe' (Managed (v4.0.30319)): Loaded 'C:\Windows\Microsoft.Net\assembly\GAC_MSIL\System.Windows.Forms\v4.0_4.0.0.0__b77a5c561934e089\System.Windows.Forms.dll', Symbols loaded.
'GaTest.vshost.exe' (Managed (v4.0.30319)): Loaded 'C:\Windows\Microsoft.Net\assembly\GAC_MSIL\System.Drawing\v4.0_4.0.0.0__b03f5f7f11d50a3a\System.Drawing.dll', Symbols loaded.
'GaTest.vshost.exe' (Managed (v4.0.30319)): Loaded 'C:\Windows\Microsoft.Net\assembly\GAC_MSIL\System\v4.0_4.0.0.0__b77a5c561934e089\System.dll', Symbols loaded.
'GaTest.vshost.exe' (Managed (v4.0.30319)): Loaded 'C:\Windows\assembly\GAC_MSIL\Microsoft.VisualStudio.HostingProcess.Utilities.Sync\10.0.0.0__b03f5f7f11d50a3a\Microsoft.VisualStudio.HostingProcess.Utilities.Sync.dll', Symbols loaded.
'GaTest.vshost.exe' (Managed (v4.0.30319)): Loaded 'C:\Windows\assembly\GAC_MSIL\Microsoft.VisualStudio.Debugger.Runtime\10.0.0.0__b03f5f7f11d50a3a\Microsoft.VisualStudio.Debugger.Runtime.dll', Symbols loaded.
'GaTest.vshost.exe' (Managed (v4.0.30319)): Loaded 'C:\Users\Lu4\documents\visual studio 2010\Projects\Estimator\GaTest\bin\Debug\GaTest.vshost.exe', Symbols loaded.
'GaTest.vshost.exe' (Managed (v4.0.30319)): Loaded 'C:\Windows\Microsoft.Net\assembly\GAC_MSIL\System.Core\v4.0_4.0.0.0__b77a5c561934e089\System.Core.dll', Symbols loaded.
'GaTest.vshost.exe' (Managed (v4.0.30319)): Loaded 'C:\Windows\Microsoft.Net\assembly\GAC_MSIL\System.Xml.Linq\v4.0_4.0.0.0__b77a5c561934e089\System.Xml.Linq.dll', Symbols loaded.
'GaTest.vshost.exe' (Managed (v4.0.30319)): Loaded 'C:\Windows\Microsoft.Net\assembly\GAC_MSIL\System.Data.DataSetExtensions\v4.0_4.0.0.0__b77a5c561934e089\System.Data.DataSetExtensions.dll', Symbols loaded.
'GaTest.vshost.exe' (Managed (v4.0.30319)): Loaded 'C:\Windows\Microsoft.Net\assembly\GAC_MSIL\Microsoft.CSharp\v4.0_4.0.0.0__b03f5f7f11d50a3a\Microsoft.CSharp.dll', Symbols loaded.
'GaTest.vshost.exe' (Managed (v4.0.30319)): Loaded 'C:\Windows\Microsoft.Net\assembly\GAC_32\System.Data\v4.0_4.0.0.0__b77a5c561934e089\System.Data.dll', Symbols loaded.
'GaTest.vshost.exe' (Managed (v4.0.30319)): Loaded 'C:\Windows\Microsoft.Net\assembly\GAC_MSIL\System.Xml\v4.0_4.0.0.0__b77a5c561934e089\System.Xml.dll', Symbols loaded.
The thread 'vshost.NotifyLoad' (0x1444) has exited with code 0 (0x0).
The thread '<No Name>' (0x3d8) has exited with code 0 (0x0).
The thread '<No Name>' (0x10a8) has exited with code 0 (0x0).
The thread 'vshost.LoadReference' (0xc40) has exited with code 0 (0x0).
'GaTest.vshost.exe' (Managed (v4.0.30319)): Loaded 'C:\Users\Lu4\documents\visual studio 2010\Projects\Estimator\GaTest\bin\Debug\GaTest.exe', Symbols loaded.
'GaTest.vshost.exe' (Managed (v4.0.30319)): Loaded 'C:\Users\Lu4\documents\visual studio 2010\Projects\Estimator\GaTest\bin\Debug\Shared.dll', Symbols loaded.
Step into: Stepping over method without symbols 'System.Collections.Generic.SortedSet<Shared.Optimization.Solution<GaTest.CurveFitSimplex,double>>.Remove'
'GaTest.vshost.exe' (Managed (v4.0.30319)): Loaded 'C:\Windows\Microsoft.Net\assembly\GAC_MSIL\System.Configuration\v4.0_4.0.0.0__b03f5f7f11d50a3a\System.Configuration.dll', Symbols loaded.