Serial Port not working

Hello,
I don't know if this is mandrake specific but my serial port just isn't
working. It worked before on MDK9.2RC1/AMD64 and on Knoppix 3.7 with 2.4
kernels.
As hardware device I am using a glucometer, setserial says this:
# setserial -ga /dev/ttyS*
/dev/ttyS0, Line 0, UART: 16550A, Port: 0x03f8, IRQ: 4
        Baud_base: 115200, close_delay: 50, divisor: 0
        closing_wait: 3000
        Flags: spd_normal skip_test

/dev/ttyS1, Line 1, UART: 16550A, Port: 0x02f8, IRQ: 3
        Baud_base: 115200, close_delay: 50, divisor: 0
        closing_wait: 3000
        Flags: spd_normal skip_test

/dev/ttyS2, Line 2, UART: unknown, Port: 0x03e8, IRQ: 4
        Baud_base: 115200, close_delay: 50, divisor: 0
        closing_wait: 3000
        Flags: spd_normal skip_test

/dev/ttyS3, Line 3, UART: unknown, Port: 0x02e8, IRQ: 3
        Baud_base: 115200, close_delay: 50, divisor: 0
        closing_wait: 3000
        Flags: spd_normal

/dev/ttyS4, Line 4, UART: unknown, Port: 0x0000, IRQ: 0
        Baud_base: 0, close_delay: 50, divisor: 0
        closing_wait: 3000
        Flags: spd_normal

/dev/ttyS5, Line 5, UART: unknown, Port: 0x0000, IRQ: 0
        Baud_base: 0, close_delay: 50, divisor: 0
        closing_wait: 3000
        Flags: spd_normal

/dev/ttyS6, Line 6, UART: unknown, Port: 0x0000, IRQ: 0
        Baud_base: 0, close_delay: 50, divisor: 0
        closing_wait: 3000
        Flags: spd_normal

/dev/ttyS7, Line 7, UART: unknown, Port: 0x0000, IRQ: 0
        Baud_base: 0, close_delay: 50, divisor: 0
        closing_wait: 3000
        Flags: spd_normal

Any ideas what could be wrong?

Thanks,
David