I have a 2nd gen Mac book air with Lion. The hard disk has filled up even though i keep my data , music etc on hard drive . I used disk inspector to find where problem was and it is 20GB in the hidden files under the user directory can i resolve this ?

Question

I have a 2nd Gen MAc book Air with Lion .  The 60GB hard disc has quickly filled up despite me keeping most of my data on a portable hard drive .  I used disk inspector to locate the problem but found that it was was in 20 GB of hidden files in my user directory .  Is this correct and is there anything i can do about it ? Using disk inspector you can not see individual hudden diretories or files. I did unhide them but there is a mass of diretories etc and so no way i could see if this is one or multiple files using the space. Library System and  Applications are at 4 3 and 3 GB respectvely.  The data I actually keep on there is 9GB    Thanks for any help

Answer 1

I think the problem is Quick Time Player. I am using OS 10.6.8 by the way.
I tried it out again.
I had about 26 GB of space before I played an .avi video.
After the movie started to play (it was slow to load), I got a warning message that my startup disk was full. I opened Disk Utility and it told me I had no space left (about 20 MB or something like that was left).
I watched to the end of the movie.
Then I quit Quicktime Player.
And I shut down the computer.
I turned on the computer and checked Disk Utility. I have about 26 GB of space.
I think for some reason Quicktime Player uses up a lot of the disk space when it runs movies that are problematic. This movie I was watching did not open with vlc.
I normally use vlc to watch movies.
Probably it doesn't use up this much space when the movie is OK.
I think there's a problem with this particular movie. It is about 50 MB so it's not that big a file. I watch .smi subtitles with it. The Quicktime Player automatically loads the subtitle file in this case because the subtitle file has the same name as the movie file.
I watched about 10 movie files from the same series that I downloaded together and did not have any problem watching them. I watched them on vlc. But this latest movie had problems I think (as I repeat). It did not load on vlc even though I waited for a minute, and normally movies load instantly on vlc. 
So I think that movie file caused problems. It made QT player use up a lot of hard disk space.
I had better avoid watching that movie in the future. I don't want it to wreck my hard drive.
So to sum up, everything is back to normal. I have the hard disk space that I should have. However, I am scared of damaging my hard drive due to shonky movie files that eat up all the space when they are played using QT player, and so I will not watch those files in the future, as I do not know why the files do that.