Checking my website stats today I saw in the list of browsers "FDM Free download manager" http://www.freedownloadmanager.org/ which is noted as being a "grabber" in the list. What is a "grabber" and should I be concerned about this? I had a quick look at the site, and it says it can be used to download entire websites - not something I would want people to be able to do! Thanks!

A download manager is a program that handle your downloads.
You can keep a list, put priorities, limit speed and such.

A grabber, in awstat terminology, is a program that will spider your site and make local copy of it.
it's this feature, in their features list:

HTML Spider :
You can download whole web pages or even whole web sites with HTML Spider. The tool can be adjusted to download files with specified extensions only.

So, as long as you don't see your bandwith going through the roof, it may simply means that they used that tool to download something from your site rather than using the browser integrated download function.
Nothing else.

Thanks! Do you know if there is any way to find out which files have been downloaded, and my main worry is that if they can download the entire site does that mean they can get into my password protected folders? Awstats says it had 54 hits, so does this mean someone downloaded 54 files of mine?