To the OP, and contrary to most of the other posts, you have my sympathy. Sometimes we feel under pressure to ignore our natural instinct over something just not feeling right, for fear of offending others or appearing prejudiced.
To everyone else who mentioned that because someone is CRB-checked then that means they are totally trustworthy, then they are being slightly naiive. Unfortunatley, there are people who are clear on a CRB check who go on to get caught and convicted for the very first time.
I speak from experience. Someone I know was convicted of paedophilia about 8 years ago. Up until that point, he had been (to all outward appearances) a fine upstanding member of the community - heavily involved in the church, had loads of experience of baby-sitting for fellow church-goers, and, last but most shockingly - working as a teacher in a primary school. The judge ruled that he had become a primary teacher mainly to gain easy access to children. To say the whole thing was a huge shock when I found out was an understatement, yet.......
.....and shoot me down in flames for this if you want to, anyone, but in hindsight there had always been something ODD about him. He had always been extremely socially awkward, a "misfit", had few if any friends, never had a proper girlfriend, spent most of his free time alone at home on a PC etc, etc. Even his body language was awkward and strange. Anybody's instinct would have told them he was just, well, a bit wierd. Yet people trusted him because he was a churchgoer and primary school teacher.
My point is, there ARE wierdos out there, and people should listen closely to their instinct, man or woman, rather than assuming that just because someone is in a position of authority that that somehow automatically makes them trustworthy. People DO slip through the net.
And before anyone has a moan, at my son's nursery there has been a male member of staff in the past (since I had experience of the above), and no, I wasn't automatically distrustful just because he was a man, or just because my beliefs might have been tainted by my experiences. On speaking to him, I felt totally at ease and there was nothing "odd" about him in any way, and I totally trusted him. And at somewhere I worked in the past there was a male nursery nurse at the creche and he was just fantastic with the kids and really good at his job, and a lovely, sociable, "normal", chatty, extremely likeable and outgoing guy.
However, I am now wondering whether my past experiences has actually coloured my judgement as looking around my son's potential primary recently, I noticed an "odd" man who was present at home time. I had already met the only male teacher previously (and again, felt no unease with him, in fact I know he is really ppopular with the kids he teaches), and so was left wondering who this man was - a caretaker? A new teacher (they had a vacancy recently)? Whatever, something about him, his body language and just his general manner and way of being around people just immediately got my hackles and suspicions up. I just didn't feel right about him and and am now thinking forward to September and wondering what contact he will have with my son and wondernig whether he's harmless.
I really do think there are not enough men in the nursery and teaching professions, and would like to see more, but unfortunately areas with easy access to children, whether it is teaching, sports coaching, scout leading, or being a church minister, will always be a huge pull for "certain types". The systems tries hard to weed out the wierdos but unfortunately some do slip through, and sometimes we really should listen to our gut instinct more where we feel someone is just "not right". We have to try and get the balance right between being competely paranoid and stupidly neurotic and suspicious of ALL men; and being naive, overly-trusting and so frantically determined to avoid being labelled prejudiced and narrow-minded that we ignore our (sometimes quite valid) natural instinct.