Sorry for the delayed response...
We will have to do some investigation on this XP SP3 LoadLibrary issue. As you noted, prior to SP3, the version number embedded in the manifest was a "minimum" version required so as long as you had installed a version compatible with that in the manifest, your app was happy.
As a workaround in your debug environment, note that you can simply link your debug app/plugin with the release versions of the OpenFlight API libraries. In fact, prior to version 4.1 (back when the debug DLLs were NOT included) that was the only way to build OpenFlight API apps (i.e., link your debug exe with Release versions of the OpenFlight API libs). You will still be able to debug your code just fine, just not the OpenFlight API functions.
In the longer term, again, we'll have to do some investigation and hopefully can sort it out for the OpenFlight API 4.2 release later this year.
One final note about the user forum... While we (at Presagis) try to address issues in a timely fashion, sometimes it just does not work out that way. Note that this forum is first and foremost intended for "Peer to Peer" interaction. If you require immediate attention (from Presagis) or would like to talk about future release requirements/schedules, we suggest contacting Presagis Customer Support directly. That way, your issue can be formally tracked and managed.
I'm working with version 4.1 of the API for 32 bits architectures, both debug and release versions, and I have realized that both depend on C Runtime (CRT) libraries from Microsoft (Microsoft.VC80.CRT and Microsoft.VC80.DebugCRT). Moreover, that dependency is included in the manifest, which is embedded in every dll file, pointing to an specific version (8.0.50727.4053) of the dependency which is not the one that can be installed with the Redistributable Package.
This is not a problem in Windows XP SP2 because LoadLibrary function does not care so much about the exact version of the dependency, but in Windows XP SP3 LoadLibrary has became more strict and you need the exact version pointed by the manifest.
For release purposes, I have downloaded the exact version and it's working properly, but to get the debug one is needed to install the same developing environment (including patches and service packs) that was used to develop the API (and I don't know which one was).
Is it planned to provide those dependencies with the API in future versions? Or even better, you could modify the embedded manifest in future versions, so it points to version 8.0.* of CRT instead of the exact one.