You're right, I've tested it, and it seems that it behaves weird. Anyhow, here's the script that works for me:
SetOEMDRO(800,0)
SetOEMDRO(801,0)
SetOEMDRO(802,0)
It will automaticaly regenerate toolpath.
I think that when DROs are defined as "standard" (codes 0,1,2) path will not be regenerated by default.
(jog follow must be turned on, i think)