From Canon USA:
imagePROGRAF PRO-1000 series Firmware Ver.1.1
- The maximum printable height of custom paper size will be lengthened to 25.5-inch (647.70mm) with specifying in the printer driver.
imagePROGRAF PRO-1000 series Printer Driver Ver.1.02
- Concerning printer paper size, the maximum height of [Paper Size] in [Custom Paper Size] is enlarged from [594mm/23.39inch] to [647.70mm/25.5inch].
When you use the enlarged paper size, use the printer with firmware version 1.110 or later.
Download: imagePROGRAF PRO-1000 series Firmware v1.1 & Printer Driver v.1.02
B&H carries the imagePROGRAF PRO-1000 printer which currently qualifies for a $100.00 mail-in rebate through August 31.