change recordlength in dpo4054

I am trying to control a tektronix DPO 4054 oscilloscope with labview 2010.

I started from the driver package that is available at ni.com.

Starting from "tkdpo4k Edge Triggered Acquisition Waveform Example.vi", I tried to change the horizontal properties such as time base and recordlength. Although the oscilloscope does use the changed recordlength, the transferred data is not consistent with that change. To reproduce this issue, I just inserted an 'array size' in the example program.

Any ideas how to fix this?

Thanks...