Brother MFC-5460CN probs - printing;scanning

Two daunting problems: Does not print in black; does not scan from software.
My os is XP sp-3

(1)Does not print in Black, either from word file print or just the 'copy Black' button on top -
just a blank page comes out.
But if the text is in color, or using the 'copy color' button, both above modes work;
Except that the b&w print from the 'color copy' button, comes out gray, not black.

Everythink else on the machine seems to work fine.
Changed black ink cartridge - did not help. Printer status monitor also shows all inks
are near near top levels.
Went into control-printer-settings and made sure it was not on color only.
Checked into forums - I see others have had this problem. But no solutions found.
Have cleaned print heads several times. No fix.
Sent a question to Brother-solutions center. No reply. No reply. No reply.
Have de-installed and re-installed to no positive effect.
Updated the firmware. No help.
PLEASE HELP

(2) Cannot setup built-in scanner from Nuance 17.
Scanner setup wizard tells to insert a disk into drive (J)
The multifunction printer itself is the drive (J) which is connected via USB
How overcome this? Are the two problems related? HELP
PS: Printer worked fine for 18 months . Now this problem.

savinir