If a <CTRL-C> or a CTRAP character arrives at certain points in ZSTEP processing, there is a small chance GT.M may ignore the <CTRL-C> or CTRAP; in a later release, <CTRL-C> and CTRAPs will always have priority over ZSTEP.

If GT.CM reports an asynchronous network error, a ZSTEP may cause the network error to go unreported; the chance of such an occurrence is small and the chance the error would subsequently be reported is high; in a later release, network errors will always be given priority over ZSTEP.