If it's a Romano multipoint system I've got the software and the programming cable :)
If it was mine, first things I'd do:-
Save a copy of the config
Check the diagnosis page for anything obvious (it just shows if the injectors are running OK)
Update the firmware to the latest version (for the Romano it's 33.0)
Perform an auto-calibration
Save another copy of the config
The last two steps this weekend solved a "tripping over to petrol under high load and high RPM" issue that's always been there, and the car feels a bit nippier too.
Mine was fitted by Phil Price, he does autogas conversions and runs a rally school where all the cars are gassed. Gave me his old programming lead too - top bloke! Don't know how much he'd charge to inspect/repair/replace your system, but like I said if it's a Romano Sequential Vapour Injection system I've got the lead and can lend it to you - just add car and laptop with a serial port! Worth checking out before shelling out. You can also check the gas and reducer (vapouriser) temperatures using the software, this could highlight issues such as an airlock in the car's cooling system (although if this is the case a Romano system will probably stay in petrol mode as it'll know that the vapouriser's not hot enough).