Jucis,
Same advice as everyone else really, just be yourself and answer the questions as truthfully as you can. If you try to put down answers that you think they are looking for, you WILL be caught out! The questionaire tends to ask a question, then 4 or 5 questions later, will ask a similar question in a different way - and by the time you get to the end of it (it veeeeeeeery long!) you have forgotten what you put at the beginning anyway!
Also, if you make it through to stage 3 (fingers crossed, I'm sure you will do fine!) they can ask you questions about your online personality questionaire - under interveiw scrutinisation, and you know what interveiwers can be like!
Also, I am told that you can only fail the Personality questionaire if you are a borderline pass in the psychometric tests at stage 1. If you pass well, then it is pretty much impossible to fail - inless you put something REALLY silly, like I like crashing aeroplanes!
Best of luck - let us know how you do!
BW