can i resume downloading an incomplete download from my library once ive quit and then restarted(if its not in the search window), just like you can on internet explorer. please help as i have tonnes of half completed files.

Just try to search and download the same files again.
You will see in the downloadwindow that if you download the same file (that is in the incomplete map) you won't start at 0% but right where you left of.

Oh dear, so this means you have to take note of the info. (probably the exact size of the file) when you download a file? Otherwise you would end up downloading the same song all over again (with different quality), right?
Being an ex-Aimster user, this proves to be a set back, as all I had do for resuming was to double click the file I wanted to resume. The software would do the searching automatically...