J. Wahl conjectured that every quasihomogeneous isolated normal singularity
admits a positive grading for which there are no derivations of negative
weighted degree. We confirm his conjecture for quasihomogeneous isolated
complete intersection singularities of either order at least 3 or embedding
dimension at most 5. For each embedding dimension larger than 5 (and each
dimension larger than 3), we give a counter-example to Wahl's conjecture.Comment: 11 page