swissis,
I don't think this problem is related to the USB port because I've seen this when using the standard LPT port.
I tried the following procedure and it seems to have worked:
> Procedure:  
> 1. Edit the registry observing usual caution.  
> 2. Locate the key HKEY_CURRENT_USER\Printers\DevModePerUser  
> 3. Remove all VALUES for Network printers of the form:  
> \<print_server_name ><printer_queue_name>  
> 4. Locate the key HKEY_CURRENT_USER\Printers\DevModes2  
> 5. Remove all VALUES for Network printers of the form:  
> \<print_server_name><printer_queue_name> 
Quoted from:
http://www.opensubscriber.com/message/samba@lists.samba.org/2097462.htmlAs for why:  
> The Windows print cache is timestamp based.  The client  
> spooler gets in a loop where it continually asks the  
> server for the timestamp (ChangeID) on a given printer.  
> In spite of the fact that the timestamp has been incremented  
> by some change to the printer, the client never updates  
> its local cache of printer data.  And so it continually  
> thinks it is out of date.
Quoted from:
http://www.opensubscriber.com/message/samba@lists.samba.org/2099674.htm