empty trash does not clear space

Hey!

When i delete items and clear empty the trash does not increase the disk space but the files is gone.
it the same on the hdd the os i installed on and on USB.
 I have to format the USB to get my space back even if i dont see any files on it, and the files isn't hidden i have tried show hidden files but doesn't show anything

ProblemType: Bug
DistroRelease: elementary OS 0.2
Package: elementary-desktop 1.284-0~355~precise1
ProcVersionSignature: Ubuntu 3.2.0-35.55-generic 3.2.34
Uname: Linux 3.2.0-35-generic x86_64
NonfreeKernelModules: nvidia
ApportVersion: 2.0.1-0ubuntu15+elementary3~precise1
Architecture: amd64
CrashDB: elementary_meta
Date: Sat Jan 19 21:05:32 2013
InstallationMedia: elementary OS 0.2 "Luna" - Beta 1 amd64 (20121114)
MarkForUpload: True
ProcEnviron:
 PATH=(custom, no user)
 LANG=sv_SE.UTF-8
 SHELL=/bin/bash
SourcePackage: elementary-meta
ThirdParty: True
UpgradeStatus: No upgrade log present (probably fresh install)