If you have an active bid on eBay we recommend that you cancel any snipe on the same item. You do not need to place a bid manually on eBay for items you are sniping - our service will place your bid on eBay using the lead time you set for the snipe. We will place your bid the number of seconds that you set for your lead time prior to the end of auction.
For more details regarding setting your snipes and having manual bids, please see our help pages: here
If you encounter any difficulty, please don't hesitate to file a support case from under the Help tab of the site so we can assist you further.