Strange Distance Draw Issues

If I fly up a ways, I get a strange distance draw behaviour:

http://www.johndriscoll.co.uk/stuff/secondlife/secondlife-linux-002.png

* Mandriva 2006 DVD (FREE)
* Gnome
* uname -a
Linux 192.168.0.50 2.6.12-12mdk #1 Fri Sep 9 18:15:22 CEST 2005 i686 Intel(R) Pentium(R) M processor 1.70GHz unknown GNU/Linux
* X.Org version: 6.8.99.900
* Section "Device"
Identifier "device1"
VendorName "Intel Corp."
BoardName "Intel 915"
Driver "i810"
Option "DPMS"
Option "VBERestore" "TRUE"
EndSection
*
* Intel Pentium M Processor 1.70GHz
* 507584K total mem

What kind of behaviour, looks like you disconnected from the neighbouring sim?

I mean that I'm pretty sure in Windows you don't see such vast distances of blue square, surrounded by nothing. On the one hand it is kind of interesting and pretty, but I'm not sure that's how it's supposed to be functioning.