We report on incoherent elastic and quasielastic neutron scattering from a symmetric poly(isoprene-1,2 butadiene) (PIP-PVE) almost athermal diblock copolymer at different wave vectors Q in the range 0.18 to 1.8 Angstrom(-1). A fixed window temperature scan between 20 K and 300 K revealed the presence of segmental dynamics above 200 K and hence line shape analysis of the incoherent quasielastic spectra S-inc(Q,omega) was performed at high temperatures far above the single glass transition T-g(=221 K) to obtain the characteristic time scales. A two step nonexponential relaxation function was found adequate to describe consistently S-inc(Q,omega) with the faster relaxation time being comparable with the segmental relaxation time in bulk PIP at similar Q. This dynamic incompatibility may arise from dynamic heterogeneities as a consequence of composition fluctuations. The observation of a bimodal relaxation distribution function in PIP-PVE with low T-g contrast at temperatures far above the single T-g emphasizes the role of the intramolecular correlations due to chain connectivity.