I know that less-is-more, but I didn't expect it with samplerates

For some reason, I felt my sunvox WAV-exports contained slightly less high frequencies when samplerate (in preferences) is set to 48000 and higher.
I might be fooling myself here, but it really seems that during realtime sunvox-playback (F10) these high frequencies from a wav-sample ARE there

I tried comparing an original WAV-sample (from a samplepack) vs an exported WAV (played by sampler in sunvox).
These frequencies only disappear during export to WAV (I tried sampling the output using a sampler, and save that WAV, but result was the same).
Here's a frequency analysis of a hihat WAV-sample, played by the sampler-module with samplerate (in preferences) set to 44100 (A) and set to 96000 (B):
I tried all Sampler interpolation-types of the sampler and/or 16/32bit exports, but it did not re-introduce the high frequencies.
Maybe the real test should be with a whitenoise wav?
Any idea?
Again, it could be that my ears are fooling me, in combination with a volume- or measurement-error
