Problem with XIPVYB_CE6Pro_V2.2_151005 and Compact Framework 2.0

I have problem to use my application in last version of CE for PiccoCOMA5, because the CF is difference 3.5 and my is 2.0
Sometime the system show me one exception :

<date>2015-11-25 15.16.41</date><code>CRITICAL_ERROR</code><pos>CaricaImpostazioniParametri()</pos><msg>The version of the assembly System, Version=2.0.0.0, Culture=neutral, PublicKeyToken=B77A5C561934E089 cannot be loaded by this version of the Microsoft .NET Compact Framework. at SplInclude.SPLS.SplTimer.SetDefault(String Tempo) at SplInterfaceUtility.SplInterface.CaricaImpostazioniParametri() at SplInterfaceUtility.SplInterface..ctor() at .() at .Main(String[] args) </msg><count>00001</count>

Before of this I used the version build for me NKVBY_CE6_MicroIT_140130, but doesn't work com2.

If possible to install the CF 2.0 in the last versione ? or fix the problem of COM2 in the versione NKVBY_CE6_MicroIT_140130 ?

I prefer the first solution

I have tryed with WEC2013/CF3.9, work, but sometime the application crash (in C#).
Crash when I open and close some forms very fast (else if I don't touch the display, work fine) .
The same project, work fine in ArmStronA9 but no in PicoComA5 !!!??.