.Net 4.0 app比64位慢32位（分析和可能的解决方案）（app正在使用NetAdvantage）

We have got .NET app written in VB .NET 4.0 / VS2010, compiled with all projects set to the AnyCPU setting for both Debug and Release configuration. We have noticed that when this app is run on a 64 bit environment (tested on Windows Server 2003 R2 and 2008 R2) that the app then takes at least double as long (in absolute terms about 25 secs) as opposed to around 6-12 seconds on a 32 bit environment (Win XP and 7) to start up.We have got .NET app written in VB .NET 4.0 / V