It seems quite odd, because for both wlan interfaces, the subnet is correct and there is traffic both ways.

So, on the N900:

inet addr:192.168.254.219
Mask:255.255.255.0
RX bytes:510308 (498.3 KiB) TX bytes:166707 (162.7 KiB)

(though the traffic is rather low here)

and on the laptop:

inet addr:192.168.254.222
Mask:255.255.255.0
RX bytes:23174401 (23.1 MB) TX bytes:5773662 (5.7 MB)


These are definitely correctly configured at the interface level.

I've occasionally had an issue ssh-ing into the N900 where the N900's lan interface needs to be "woken up" by initiating some traffic from the device itself.

"No route to host" might be a connect timeout, if the wlan interface on the N900 has gone to sleep (the message might take a while to appear if this is the case.)

I would first make sure there's no interference from iptables on the laptop by turning iptables off temporarily, then make sure the interfaces and routing are as described previously on both machines, then try pinging the laptop IP from the N900, and if you get replies, try to ssh to the N900 from the laptop again.

If that doesn't work, might be best to post your laptop routing table, though from looking at the ifconfig output it seems it would be correct.