Comment 12 for bug 730225

Wei-Yee Chan wrote on 2011-03-13:

>I don't know how I got "infected" with FlexNet. All the while, grub hadn't
>be causing any problems and nothing on my Windows system had changed,
>with the exception of a few updates.

You or other people may have installed some adobe product or some other software and then uninstalled to leave this sector there.

>You do think that changes in grub2 caused this, don't you? Well, I think
>so too.

Yes. This is caused by the bad way the new grub2 responds to https://bugs.launchpad.net/ubuntu/maverick/+source/grub2/+bug/441941
Earlier versions of grub2 just overwrites the flexnet sector(s). But in your case, flexnet sector 50 locates after the end of the core image and survived.
In my opinion, grub2 shouldn't dance with these windows softwares just to add complexities and difficulties. If such sectors are detected, just refuse to install grub2 and use grub legacy instead.