ive spent around a day getting Multicraft running on my VPS
Ive got multicraft running but when i try create a server and start it up

i get these errors

29.03 11:08:15 [Multicraft] Loading server properties
29.03 11:08:01 [Multicraft] Server stopped
29.03 11:08:01 [Multicraft] Received stop command
29.03 11:07:59 [Multicraft] Server stopped
29.03 11:07:59 [Multicraft] Looks like a crash, check the server console. Return value: 1
29.03 11:07:59 [Multicraft] Server shut down
29.03 11:07:59 [Server] INFO Error: Invalid or corrupt jarfile /jar/craftbukkit.jar
29.03 11:07:59 [Multicraft] Loaded config for "Mod: Craftbukkit"
29.03 11:07:59 [Multicraft] Starting server!
29.03 11:07:59 [Multicraft] Loading server properties
29.03 11:07:59 [Multicraft] Server stopped
29.03 11:07:59 [Multicraft] Retrying server startup
29.03 11:07:54 [Multicraft] Server stopped
29.03 11:07:54 [Multicraft] Looks like a crash, check the server console. Return value: 1
29.03 11:07:54 [Multicraft] Server shut down
29.03 11:07:54 [Server] INFO Error: Invalid or corrupt jarfile /jar/craftbukkit.jar
29.03 11:07:54 [Multicraft] Loaded config for "Mod: Craftbukkit"
29.03 11:07:54 [Multicraft] Starting server!
29.03 11:07:54 [Multicraft] Loading server properties
29.03 11:07:54 [Multicraft] Server stopped
29.03 11:07:54 [Multicraft] Retrying server startup
29.03 11:07:49 [Multicraft] Server stopped
29.03 11:07:49 [Multicraft] Looks like a crash, check the server console. Return value: 1
29.03 11:07:49 [Multicraft] Server shut down
29.03 11:07:49 [Server] INFO Error: Invalid or corrupt jarfile /jar/craftbukkit.jar
29.03 11:07:49 [Multicraft] Loaded config for "Mod: Craftbukkit"

can anyone help?

To fix this as it says that its invalid or corrupt i uploaded the craftbukkit.jar with my FTP
didnt work same problem, so then i tried updating multicraft's minecraft.jars i get this error:

craftbukkit_beta.jar: Error downloading update: HTTP Error 403: Forbidden

PLEASE i need a Fix As fast as possible!

Thanks