I have discovered a down-side of commercial software: I have an installation of Mathematica 5.2. After recompiling my Linux kernel (I just added the ethernet driver in the kernel), my "machine ID" changed and I had to request a new license from Wolfram Research. It was relatively painless to get a new license code (this time!). At best, this relicensing is a minor nuisance, but at its worst, the Wolfram research might get suspicious and make it very hard for me to get a new license in the future (if I do it too often). So now it seems that I'm stuck with Linux 2.6.12 kernel in its current configuration.
Does anyone have more experience with Wolfram and "system transfer requests"?