In a multi-nozzle piezo-electrically driven print head a large number of miniature and valveless pumps are integrated. In order to have a design with the smallest native nozzle pitch possible the pumps are placed as closely as possible next to each other. This implies that the length of the pump chamber has to be long compared to its cross-sectional dimensions in order to enable the piezoelectric actuator to generate enough volume displacement. The layout of such a pump is of the waveguide type and upon actuation waves start to travel back and forth through the pump chamber. The evolution of these waves in course of time depends on the reflection properties at the beginning and the end of the pump chamber, the beginning being the connection to the main ink supply and the end being the nozzle. The attenuation depends on the viscosity of the ink used. At the end of the nozzle a meniscus is formed. In the case the meniscus retracts over a small distance into the nozzle its curvature increases and the capillary pressure increases. This effect forces the meniscus to move back to its original position. During outflow over a small distance the same happens. With increasing outflow the curvature increases and the capillary force opposing the motion increases accordingly. The capillarity builds a kind of mechanical spring action. This spring action together with the mass of fluid in the pump forms a massspring system with its own oscillatory behavior. The resonance phenomenon is the so-called slosh-mode, all the fluid contained in the pump moves in phase against the surface tension spring. For higher order meniscus modes, however, the fluid motion is confined to the very close environment of the meniscus. When the print head and the pulse are designed such that an overtone of the waveguide coincides with an axisymmetric higher order oscillation of the meniscus it is possible to make droplets that are much smaller than the standard droplet metered by the nozzle diameter. When such an overtone coincides with a non-axisymmetric mode, straightness errors may be induced. The paper will discuss an enhanced theory on higher order axisymmetric and nonaxisymmetric meniscus oscillations and their possible effects on droplet formation and straightness errors.