a recursive crash resizing windows

Hello.
I have a crash of sl 1.18.4 client every time I try to resize window or minimize it to tray
I use Ubuntu 7.10.

Maybe a problem related to graphic card?

Thanks.

Here you have some info:
--------------------------------------------
Second Life 1.18.4 (3) Nov 7 2007 11:12:54 (Second Life Release)

CPU: Intel(R) Core(TM)2 CPU 6600 @ 2.40GHz
Memory: 2025 MB
OS Version: Linux 2.6.22-14-generic #1 SMP Sun Oct 14 23:05:12 GMT 2007 i686
Graphics Card Vendor: NVIDIA Corporation
Graphics Card: Quadro FX 3450/4000 SDI/PCI/SSE2
OpenGL Version: 2.1.1 NVIDIA 100.14.19
LLMozLib Version: 1.1.0 (Mozilla GRE:1.8.0.12_0000000000)
Packets Lost: 0/8890 (0.0%)
Viewer Digest: d6b6010f-333a-99dd-c765-3b7e76fda5e0

frequently when I resize the SL window the whole window freezes and turns blackbut if I wait 4 or 5 minutes SL comes back.

I'm using Kubuntu Feisty and have a Nvidia 7900 graphics card