Given the age of this question I'm hoping you've already figured out your issue, but, for the sake of anyone who finds this question with the same issue in the future, I wanted to highlight the cause that I have found to be the most common in my experience.
Duplicate binaries, as mentioned by Raj, are a fairly common issue arising from situations where two different binary items in Tridion share a file name and are being published from the same publication. Since Tridion attempts to place all files into the same folder on the file system by default in many implementations there will obviously be a unique filename conflict with the second binary. I wouldn't be surprised if the component blocking publishing in this case contains a duplicate binary. The deployer logs would show this pretty clearly. There are ways to get around this programmatically if you're running into the issue repeatedly, but the simplest solution is to just make sure all binary filenames are unique.
For more detail you can check out Chris Summers' comprehensive blog post here.