[Test-Equipment] HP 33120A need for calibration?

[davec]

HP 33120A arbitrary waveform synthesizer has option 001 which adds 10 
MHz sync signal and input and output BNC connectors on the rear 
panel. I've connected two of these in "sync lock" fashion as 
described by the option 001 manual. I set identical sine wave, 100 
KHz, 500mV, 0 deg. phase offset parameters for both gens.

When I view the two outputs from both gens (using a Tek 2467b scope), 
the signals are identical, but are shifted by about 40 degrees. 
Shouldn't these be locked together, in phase? (I swapped outputs 
between several of the scope's channels, but all seem to confirm the 
same story.)

I've gone back over the parameter settings and I can only come to the 
conclusion that one or both of these gens is out of calibration. If 
so, is this something that can be corrected by a "self calibration" 
procedure (ie, a "software calibration")? Or is this something that 
needs to be tweaked "by the hand of man" (pots and such)?

Thanks,
Dave