I have had my CT2ooh for 9 months, I have had a problem with the cruise control sometimes working and sometimes not working it has been back to dealer on 4 occassions with no fault found, I discovered that if the engine braking lever was used this would cancel the cruise control (as with normal braking) but it would not allow the cruise control to be set again, the only way to reset it is to stop and turn off all power then restart. I have pointed this out to he dealer who have contacted Lexus to find out if it is a safety feature or a fault. Meanwhile as I use the cruise control regular I don't use the engine braking system and it works fine. Hope this helps.
Further update:- After further investigating I have discovered that when the engine braking system is used the cruise control can be reset by moving the shift lever back to drive position, this tells the ECU Unit that normal driving has resumed also the blue background dashboard light returns to indicate this. I have searched through the Owners manual but there is no mention of this.