I read a book by Azizi Ali about auctions and also spent some time with the largest auction banks in Malaysia recently.
Both Azizi Ali and the person at the auction bank seemed to say that if you do your homework you can get great bargains. In fact the person at the bank bought some properties himself which he sold for a profit. It seems that if you know what you are doing it's safe, but if not, I suppose it's not.
Before you start bidding make sure you know what price you are prepared to pay, and NEVER exceed that price during the auction. Don't let it become a competition as you do not want to buy at a price that you have decided in the heat of the moment - you need to be as cool as a cucumber - if the price is not good you must just walk away.
I also discussed a concern I had with the person at the largest auction bank in Malaysia - I asked him about these syndicates that operate and ask you for money to stop them from bidding. Rather than you pay a higher price because both of you are bidding you pay him a small bribe and save money - he said that you should just ignore them. Or ask them to pay you the bribe, which they will never do, because they are not interested in the property in the first place. They simply will not bid if they do not want the property - so ignore them. For them, if they bid and then no-one bids after them they have to buy the property or lose their deposit, so they will never risk bidding when they do not want to buy.