Pocket PC 2002 SDK

So far I have had quirks of various severity with all the software I have released when running on Pocket PC 2002. Some issues I attributed to GAPI differences on the new hardware. However, with DEXplor I use only straight Windows API stuff. I build using the Pocket PC SDK that came out when Embedded Visual Tools was released, so it is a few years old. Some questions:
Are apps produced with the original Pocket PC SDK 100% compatible with Pocket PC 2002 devices, or are there some known issues? They most certainly are "supposed" to run fine on PPC 2002, but that's not really my question.
If I build an app with the Pocket PC 2002 SDK will it be backwards compatible and run on Pocket PC devices? That of course assumes I do not call any of the new PPC 2002 API functions.
Does the Pocket PC 2002 SDK coexist with the existing Pocket PC SDK, or does it replace it during installation? If the answer to question 2 is yes then this isn't such an issue.
Thanks.
Dan East
Are apps produced with the original Pocket PC SDK 100% compatible with Pocket PC 2002 devices, or are there some known issues? They most certainly are "supposed" to run fine on PPC 2002, but that's not really my question.

If I build an app with the Pocket PC 2002 SDK will it be backwards compatible and run on Pocket PC devices? That of course assumes I do not call any of the new PPC 2002 API functions.
Does the Pocket PC 2002 SDK coexist with the existing Pocket PC SDK, or does it replace it during installation? If the answer to question 2 is yes then this isn't such an issue.
Thanks.
Dan East