Thanks, you're probably right. Is there a list of all the improvements in the new firmware?
Nothing from Rigol unfortunately. These are all (IIRC) that have been noted by users so far:
New feature: Manual cursors has DisplayMode X-Y.
New feature: Cursors in X-Y mode.
New feature (as option): CAN trigger and decode.
Bug fix: RS-232 baud rate at AUTO 57600.
Bug fix: Bus decoding of full ASCII character set.
Improved: Faster waveform update rates at lower time bases.
Improved: Intensity grading in Delayed Sweep (Zoom) mode.
Improved: FFT functioning.