In my last project, we had 8 builds, and i used 2 get build 
every week.

ok.

There are two types of builds: release and debug. Always set
the build type to release for builds that are shipped to
customers. The debug build is frequently used during the
development phase of the application. Both types of builds
can be debugged, and both types of builds must have symbols
to debug them. One important difference is that the release
setting in Visual C++ turns on compiler optimization and the
debug setting turns compiler optimization off. When compiler
optimization is turned on, the application runs faster.
However, it is not as easy to step through the code because
the source code lines are not compiled in the exact order
that they appear in the source code. Therefore, during the
development phase of a project, it is easier to debug a
debug build.

In both the Visual C++ 6.0 and the Visual C++ .NET
development environments, you can create a debug build by
selecting debug as the build type, and you can create a
release build by selecting release as the build type. If you
are not using the Visual C++ development environments, you
must know what compiler and linker options to set.

To enable debugging of a release build for Visual C++ .NET
or for Visual C++ 6.0, change the following compiler options
on the Cl.exe compile of your build:
Compiler

    * Enable /Z7 for Visual C++ .NET
    * Enable /Zi for Visual C++ 6.0
    * Enable /O2

For additional information about the Compiler option, visit
the following Microsoft Developer Network (MSDN) Web site:
http://msdn.microsoft.com/en-us/library/aa236704.aspx
(http://msdn.microsoft.com/en-us/library/aa236704.aspx)
Linker

    * Select/INCREMENTAL:NO
    * Select /DEBUG:Yes
    * Select /OPT:REF
    * Select /OPT:ICF

For additional information about the Linker option, visit
the following MSDN Web site:
http://msdn.microsoft.com/en-us/library/aa270751.aspx
(http://msdn.microsoft.com/en-us/library/aa270751.aspx)
Enable Debugging in a Release Build in Visual C++ 6.0
To enable debugging in a release build in a Visual C++ 6.0
development environment, follow these steps:

   1. On the Project menu, click Settings.
   2. Click Win32 Release configuration.
   3. On the C/C++ tab, click General, and then set the
following:
          * Set Optimizations to Maximize Speed or to
Minimize Size.
          * Set Debug Info to Program Database.
   4. On the Link tab, click General, and then set the
following:
          * Make sure that you click to select Generate
debug info.
          * Make sure that you clear the Link incrementally
check box.
   5. Edit the Project options directly, and then add
/opt:ref,icf.

You can now debug your release build application. To find
the problem, step through the code until you find where the
failure occurs, and then determine the incorrect parameters
or code. If a program works in a debug build, but fails in a
release build, it is likely that one of the compiler
optimizations is exposing a defect in your source code.

To create a debug build, use the following options:
Compiler

    * Enable /ZI
    * Enable /Od

Linker

    * /debug
    * /incremental:yes

After you have completed the steps, and you recompile the
application, you will have .pdb files in either the \Debug
or the \Release directory of your project, depending on your
build configuration.