There's an apparent conflict between two excellent dashboard widget plugins for MT: DashOff and MyBlogs. They don't play well together--if you use one, the other won't show up.
The conflict is in their respective perl files, MyBlogs.pl and DashOff.pl, which are bundled with the plugins.
Both of them use variable with the same name: my @blogs / $blogs, and my $perms / $perms
Assuming that you want to use both of them at once (who wouldn't?), you need to change the names of these two parameters (perhaps only the first, but I haven't bothered to test that) in one of the two files.
Therefore, in DashOff.pl for instance, you should change every occurrence of $blogs to something else, like $blogset, change my @blogs to my @blogset; and similarly change my $perms / $perms to my $perms2 / $perms2
Once you've done that, both work together.
Reported on Movable Type 4.2

Actually, this is not the reason for the conflict. The conflict occurs because DashOff has a bug whereby it specifies the same unique identifying key for the widget it provides as MyBlogs. To resolve:
Thanks Arvind.
Actually, I'd renamed that to my_blogset ... didn't think to stop there, though :-)
DashOff v1.1 released.
Fantastic, Beau!