Problem with serial-multi-port-card

Hi,

to access our different unix- and linux-server via a serial console, I
took a PC, put in a serial-multi-port-PCI-card (8-port) and installed
it with RHEL AS4 (Kernel 2.6.9-5.EL).
Redhat recognized the multi-port-card.
Here the output of "lspci -vv":

00:10.0 Serial controller: Timedia Technology Co Ltd PCI2S550 (Dual
16550 UART) (rev 01) (prog-if 02 [16550])
Subsystem: Timedia Technology Co Ltd: Unknown device 4066
Control: I/O+ Mem- BusMaster- SpecCycle- MemWINV- VGASnoop- ParErr-
Stepping+ SERR- FastB2B-
Status: Cap- 66Mhz- UDF- FastB2B+ ParErr- DEVSEL=medium >TAbort-
<TAbort- <MAbort- >SERR- <PERR-
Interrupt: pin A routed to IRQ 11
Region 0: I/O ports at a800 [size=32]
Region 1: I/O ports at ac00 [size=16]
Region 2: I/O ports at b000 [size=8]
Region 3: I/O ports at b400 [size=8]
Region 4: I/O ports at b800 [size=8]
Region 5: I/O ports at bc00 [size=8]

As you see, linux only find 6 ports... not 8... this is my first
problem. How can I tell him, that there are still 2 ports more??

My other problem is, that from the 6 recognized serial-ports, only two
works. Only the ports ttyS4 and ttyS5 works.
Both internal serial-ports works, too.
Here is the output from "ls -l /dev/ttyS*":

crw------- 1 root root 4, 64 9. Mär 15:55 /dev/ttyS0
crw-rw---- 1 root dial-out 4, 65 21. Mär 08:47 /dev/ttyS1
crw-rw---- 1 root dial-out 4, 66 22. Mär 09:00 /dev/ttyS2
crw-rw---- 1 root dial-out 4, 67 14. Mär 10:25 /dev/ttyS3
crw-rw---- 1 root dial-out 4, 68 22. Mär 09:01 /dev/ttyS4
crw-rw---- 1 root dial-out 4, 69 17. Mär 09:20 /dev/ttyS5
crw-rw---- 1 root dial-out 4, 70 14. Mär 09:14 /dev/ttyS6
crw-rw---- 1 root dial-out 4, 71 14. Mär 09:19 /dev/ttyS7

/dev/ttyS0 and /dev/ttyS1 are the internal serial-ports. With the group
"dial-out" I entitle some non-root-users the use of the serial-ports.

What I have noticed is, that the IO-port-address of the working
serial-ports are in the same range. In the output of "cat
/proc/tty/driver" you can see it:

serinfo:1.0 driver revision:
0: uart:16550A port:000003F8 irq:4 tx:8208 rx:0 RTS|DTR
1: uart:16550A port:000002F8 irq:3 tx:14 rx:738 CTS|DSR
2: uart:16550A port:0000B400 irq:10 tx:61 rx:0
3: uart:16550A port:0000B800 irq:10 tx:189 rx:64
4: uart:16550A port:0000AC00 irq:10 tx:976 rx:1745 fe:11 brk:3 CTS|DSR
5: uart:16550A port:0000AC08 irq:10 tx:81 rx:2385 fe:14 CTS|DSR|CD
6: uart:16550A port:0000B000 irq:10 tx:118 rx:5 brk:2
7: uart:16550A port:0000B008 irq:10 tx:16 rx:0

There you can see, that ttyS4 and ttyS5 have the IO-port-range
0000AC0x... but I was not able to change the IO-port-address of the
other serial-ports with "setserial".

Anybody an idea?!