You are right that theoretically the MI interpreter as such should be independent of the platform.
I did however observe that between Ubuntu 7.04 and 7.10 there have been some configuration changes that could affect some variable settings in the installation. In other words I could see this being a weird side effect of an installation problem.
Anyway - we'll investigate this further with the information you provided and do some cross checks against different debugger installation.
I'l let you know if we find a workaround. Our next major update will of course be fully validated against Ubuntu 7.10. I am sorry that it is always slightly tricky to sync the major OS version updates with our own relase schedules.
Thanks, Rob