Got this log while got the patch downloaded:

Log start : Tue Dec 18 14:33:03 2012

Current Directory : C:\Users\Beheerder\Downloads\GunZ
14:33:03:152 [APP] OS version : Service Pack 1 (Build 7601)
14:33:03:168 [APP] Window created successfully.
14:33:05:343 [ZUpdate] Create.
14:33:05:344 [ZFileTransfer] Create.
14:33:05:344 [ZFileTransfer] Create successfully complete.
14:33:05:346 [ZFileTransfer] Open connection.
14:33:05:347 [ZFileTransfer] Open connection successfully complete.
14:33:05:347 [ZFileTransfer] Change directory.
14:33:05:349 [ZFileTransfer] Change directory successfully complete.
14:33:05:349 [ZUpdate] Create successfully compete.
14:33:05:369 [APP] Download patch info file
14:33:05:369 [ZUpdate] Start update.
14:33:05:370 [ZFileTransfer] Download file : ./patch.xml to ./patch.xml
14:33:06:314 [ZFileTransfer] Download successfully complete.
14:33:06:314 [ZUpdate] Get update info.
14:33:06:340 [ZUpdate] Get update info successfully complete.
14:33:06:342 [ZUpdate] Check valid from patch list.
14:33:17:101 [ZUpdatePatchNode] Needs to update : ./Gunz.exe
14:33:18:645 [ZUpdate] Check valid from patch list successfully complete.
14:33:18:645 [ZUpdate] + Total patch file count : 1
14:33:18:645 [ZUpdate] + Total patch file size : 3640000 bytes
14:33:18:645 [APP] Exist patch file(s)
14:33:18:645 [APP] Start file updating...
14:33:18:645 [ZUpdate] Patch files.
14:33:18:645 [ZFileTransfer] Download file : ./Gunz.exe to C:\Users\Beheerder\Downloads\GunZ\PATCH\Gunz.exe_
14:33:18:676 [ZFileTransfer] Download successfully complete.
14:33:18:676 [ZUpdate] Successfully download '.\PATCH\Gunz.exe_'
14:33:18:676 [ZUpdate] Patch files successfully complete.
14:33:18:676 [ZUpdate] Move patch files.
14:33:18:676 [ZUpdate] ERROR : Invalid CRC '.\PATCH\Gunz.exe_'
14:33:18:676 [ZUpdate] Move patch files successfully complete.
14:33:18:676 [ZUpdate] ERROR : Cannot move patch files.
14:33:18:676 [APP] ERROR - Update fail
14:33:18:676 [APP] Updater error message :

Invalid CRC from the downloaded patch file. : .\PATCH\Gunz.exe_
[Tip] Please check for anti-virus program or firewall running on your system.

14:33:18:676 [App] File transfer error message :


hope someone can help me

Try completely reinstalling (delete old folders/files after you uninstall). Update using aeria ignite or gunzlauncher.exe. Close background applications that might be conflicting with GunZ. Make sure your firewall allows gunz through it, and try turning it off as well.