Can't config cups printer, no backends found

[T o n g <mlist4suntong@yahoo.com>]

Hi,

I can't config my cups printer in my newly installed lenny system. I 
found that the reason might be that no cups backends can be found, 
because previously, 

 /usr/lib/cups/backend/usb

can returns my printer info, now it is empty. How should I fix it? 

thanks

PS. my cups:

$ dpkg -l *cups* | grep ^i
ii  cups           1.3.8-1lenny1  Common UNIX Printing System(tm) - server
ii  cups-bsd       1.3.8-1lenny1  Common UNIX Printing System(tm) - BSD comman
ii  cups-client    1.3.8-1lenny1  Common UNIX Printing System(tm) - client pro
ii  cups-common    1.3.8-1lenny1  Common UNIX Printing System(tm) - common fil
ii  cups-driver-gu 5.0.2-4        printer drivers for CUPS
ii  cupsys         1.3.8-1lenny1  Common UNIX Printing System (transitional pa
ii  cupsys-bsd     1.3.8-1lenny1  Common UNIX Printing System (transitional pa
ii  cupsys-driver- 5.0.2-4        printer drivers for CUPS
ii  libcups2       1.3.8-1lenny1  Common UNIX Printing System(tm) - libs
ii  libcupsimage2  1.3.8-1lenny1  Common UNIX Printing System(tm) - image libs


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