I repeatedly encounter a warning saying "Your startup disk is almost full."

What I did:

1. I click on the startup disk icon, press command+I and it shows the available space is 46.61GB, which I think is quite enough.

2. I run disk utility to repair the permissions. Permissions are fine.

3. I reboot with the DVD, run the disk utility again to repair my startup disk. It says the volume is OK.

What machine I am using:

Hardware:

Intel Pentium Dual-Core E2160 oc 2.4GHz
Gigabyte EG31MF-S2 (Intel G31 + ICH7)
nVidia GeForce 7300GT with 256MB GDDR3
2GB DDR2-800 *2 = 4GB RAM
320G SATA -- Windows Vista Ultimate with SP1
160G SATA -- Mac OS X Leopard 10.5.6

Software:

iPC OSX86 Final (I used to run the Mac OS X 10.5.5 installed from retail DVD, but I have problems upgrading it to 10.5.6, that's why I turned to iPC OSX86)
iLife 09
iWork 09
Adobe CS3 Design Suite
Aperture 2
VMWare 2.0, with ONE virtual machine: HDD was set to 40GB and increasing its size automatically.
uTorrent for Mac


I found the reason.

uTorrent for Mac caused this false warning.

http://forum.utorrent.com/viewtopic.php?id=49896