While inserting a pci module (For Ethernet Card) following error is coming.

insmod: error inserting 'pci_driver.ko': -1 No such device

I am using 2.6.18 kernel. The same driver and hardware is working in 2.6.6 kernel. In 2.6.18 the probe function is called. I am returning 0 in the probe function. After that "remove" function called by os. If probe is success why OS is calling the remove function. If probe return 0 means driver has accepted the hardware, then why the remove function is called?

The lsmod and lspci output are as follows.

Our pci device is the following one:
01:00.0 Ethernet controller: Unknown device 1869:0011

Is there some module already loaded those are creating problem?

lsmod output:
Module Size Used by
i915 23168 2
drm 72596 3 i915
autofs4 25604 2
hidp 24064 2
rfcomm 45976 0
l2cap 31744 10 hidp,rfcomm
bluetooth 58596 5 hidp,rfcomm,l2cap
sunrpc 158524 1
acpi_cpufreq 13188 0
dm_mirror 26064 0
dm_multipath 22536 0
dm_mod 61336 2 dm_mirror,dm_multipath
video 20996 0
sbs 20288 0
i2c_ec 9344 1 sbs
button 11152 0
battery 14468 0
asus_acpi 20760 0
ac 9604 0
ipv6 266144 18
parport_pc 31268 1
lp 17096 0
parport 40776 2 parport_pc,lp
floppy 61348 0
snd_intel8x0 36508 0
snd_ac97_codec 95136 1 snd_intel8x0
snd_ac97_bus 6656 1 snd_ac97_codec
snd_seq_dummy 8196 0
snd_seq_oss 37248 0
snd_seq_midi_event 11904 1 snd_seq_oss
snd_seq 57072 5 snd_seq_dummy,snd_seq_oss,snd_seq_midi_event
snd_seq_device 12556 3 snd_seq_dummy,snd_seq_oss,snd_seq
snd_pcm_oss 46464 0
snd_mixer_oss 20736 1 snd_pcm_oss
snd_pcm 80388 3 snd_intel8x0,snd_ac97_codec,snd_pcm_oss
snd_timer 27140 2 snd_seq,snd_pcm
snd 56964 9 snd_intel8x0,snd_ac97_codec,snd_seq_oss,snd_seq,snd_seq_device,snd_pcm_oss,snd_mixer_oss,snd_pcm,snd_timer
soundcore 14176 1 snd
8139cp 28416 0
8139too 31232 0
mii 9856 2 8139cp,8139too
serio_raw 11268 0
pcspkr 7424 0
snd_page_alloc 14344 2 snd_intel8x0,snd_pcm
i2c_i801 11916 0
i2c_core 25600 2 i2c_ec,i2c_i801
ata_piix 17928 0
libata 102036 1 ata_piix
sd_mod 24832 0
scsi_mod 138152 2 libata,sd_mod
ext3 134920 3
jbd 62504 1 ext3
ehci_hcd 35208 0
ohci_hcd 23812 0
uhci_hcd 27276 0

lspci Output:

00:00.0 Host bridge: Intel Corporation 82945G/GZ/P/PL Memory Controller Hub (rev 02)
00:02.0 VGA compatible controller: Intel Corporation 82945G/GZ Integrated Graphics Controller (rev 02)
00:1c.0 PCI bridge: Intel Corporation 82801FB/FBM/FR/FW/FRW (ICH6 Family) PCI Express Port 1 (rev 03)
00:1d.0 USB Controller: Intel Corporation 82801FB/FBM/FR/FW/FRW (ICH6 Family) USB UHCI #1 (rev 03)
00:1d.1 USB Controller: Intel Corporation 82801FB/FBM/FR/FW/FRW (ICH6 Family) USB UHCI #2 (rev 03)
00:1d.2 USB Controller: Intel Corporation 82801FB/FBM/FR/FW/FRW (ICH6 Family) USB UHCI #3 (rev 03)
00:1d.3 USB Controller: Intel Corporation 82801FB/FBM/FR/FW/FRW (ICH6 Family) USB UHCI #4 (rev 03)
00:1d.7 USB Controller: Intel Corporation 82801FB/FBM/FR/FW/FRW (ICH6 Family) USB2 EHCI Controller (rev 03)
00:1e.0 PCI bridge: Intel Corporation 82801 PCI Bridge (rev d3)
00:1e.2 Multimedia audio controller: Intel Corporation 82801FB/FBM/FR/FW/FRW (ICH6 Family) AC'97 Audio Controller (rev 03)
00:1f.0 ISA bridge: Intel Corporation 82801FB/FR (ICH6/ICH6R) LPC Interface Bridge (rev 03)
00:1f.1 IDE interface: Intel Corporation 82801FB/FBM/FR/FW/FRW (ICH6 Family) IDE Controller (rev 03)
00:1f.3 SMBus: Intel Corporation 82801FB/FBM/FR/FW/FRW (ICH6 Family) SMBus Controller (rev 03)
01:00.0 Ethernet controller: Unknown device 1869:0011
02:0b.0 Ethernet controller: Realtek Semiconductor Co., Ltd. RTL-8139/8139C/8139C+ (rev 10)

Thanks,
Debasish