Msiexec fails to run (command generated with NANT)

Question

The following is used to generate an msiexec command with nant:

> "<exec program="msiexec"
> timeout="1800000" verbose="true">
>             <arg line="/i &quot;${server.msi}&quot;" />
>             <arg line="TARGETDIR=&quot;${server.target.path}&quot;"
> />
>             <arg line="INSTALLDIR=&quot;${server.target.path}&quot;"
> />
>             <arg line="ALLUSERS=1" />
>             <arg line="/quiet" />
>             <arg line="/log &quot;${path::combine(log.path,
> 'Installation.Server.log')}&quot;" />"

        </exec>

Th generated command is: msiexec ( /i "S:\Work\Sources\Installation\Setup\LastBuild\WiseSetup Server.msi" TARGETDIR="C:\Program Files\MyProgs\Server" INSTALLDIR="C:\Program Files\MyProgs\Server" ALLUSERS=1; /quiet /log "C:\Projects\P3450\Environment\Logs\Installation.Server.log")

this command fails to execute when the /quiet (or /qn) is removed it runs successful. Otherwise it gives the error: External Program Failed: msiexec (return code was 1619)

Note that of the "(" and ")" is removed and the /quiet is there it runs successful !