Ad-hoc routing problem

[Björn Süß]

Hi, 

I got a little problem which I can't solve myself. We are trying to connect 
three windows and one linux pc via the ad-hoc modus. Running the linux pc as 
an access point works fine, but unfortunatly is no option for us.
Linux uses hostap_pci V.0.2.0 

The simplified setup:
Windows 1 : IP 192.168.50.1 MAC: 01:01:01:01:01:01
Windows 2:  IP 192.168.50.2 MAC: 02:02:02:02:02:02
Windows 3:  IP 192:168.50.3 MAC: 03:03:03:03:03:03
Linux        : IP 192.168.50.4  MAC: 04:04:04:04:04:04

The Windows pc can ping each other, can see there netbios shares etc. The 
Linux pc got an connection with MAC: 02:02:02:02:02:02 or 01:.... depends on 
the signal quality. Iptables is set to ACCEPT everything. 

#route
Ziel            Router          Genmask         Flags Metric Ref    Use Iface
192.168.50.0        *               255.255.255.0   U     0     0     0 wlan0

#ping 192.168.50.1
Nothing happens

Tried to log the connection via tcpdump. When sending a ping the following 
packets are logged:
Source                    Target      ARP   Info
04:04:04:04:04:04 ff:ff:ff:ff:ff:ff      Who has 192.168.50.1 tell192.168.50.4

This is repeated nearly endless. Besides this only these packets have been
captured:
Source                 Target                      STP
02:02:02:02:02:02   04:04:04:04:04:04
Info
Conf. Root = 32768/02:02:02:02:02:02 Cost = 0 Port = 0x8001
What does this spanning tree protocol want?

Last thing I figured out, if root enters the arp command the IPs are sometimes 
listed with their MAC address, but half a second later they got lost.

Any suggestions? Do I have to compile the kernel with special routing options? 
Do I need to set up arp manually....