As long as a bid is over 2.00 it is valid so a bid of 2.01 is a valid bid.
For Example..... you are the first person to bid on a lot that starts at 5.00 and you decide to bid 15.00 as your max. You enter 15.00 and the auction says "you are winning this lot at 5.00" you have another 10.00 in proxy that only you know about so if some one bids 10.00 or less you would continue to win this lot as the system bids for you in 2.00 increments until someone bids higher than your MAX proxy so if someone bid 15.01 they would be the new lead bid by a penny.
You will notice a lot of seasoned bidders bid in odd increments just so they can defeat a proxy bid and get the item for as little as possible. It's a strategic bidding approach a lot of people now use with online bidding.
....so by entering odd bid amounts (even a penny) you can actually save yourself the price of a coffee if you adopt this strategy.