yes more than likley condensation in the cap and the spark plug was it put in tight enough in the first place ?
how long has she had the car if she's not had it that long she wants to be taking it back,the plug thing might have happend before and thats why they got rid ?
i've got a 1992 110 that fires first turn then stops ! but thats got a leak on the injector pump starts upagain no problem but it will need doing as its not going to get any better !