They designed it to be scary shit Peter. Don't believe the hype. I do agree that the sensor is easily tricked, but water just doesn't get absorbed like that unless you leave the tank cap off in the rain.
Daz dropped his GTR off here for fabrication after his 2630 was built, we drained the tank as it had been sitting in Barry's workshop for a year and a half with no engine, open fuel lines and rail. After cleaning the injectors and lines he didn't want to run the old fuel, so I drained it and put in in my evo.
Thanks for the free fuel Darren, it ran fine at 32 pounds. AFR's were perfect, no det obviously.