From what I read you have to be using superblock (--metadata=) version 1 to do that, right? Not 0.90? I thought I read that somewhere. It seems the default setting, at least for Ubuntu 10.04, is --metadata=0.90 but I'm not entirely certain.
Not sure if it is absolutely necessary or not, but FWIW it looks like we're using 1.02. It has been a while since I set it up, but IIRC I used an Ubuntu live CD to build the new RAID set, so I probably did use the --metadata option. (The actual server is running Debian Lenny...)
In other Debian/Ubuntu news, it looks like using Remote Desktop to access a system with desktop effects enabled doesn't result in a train wreck any more. This was one of the things which had previously caused me to add "disable desktop effects" to my checklist of things to do on all new Linux installs. I'm also quite pleased to discover that the IGP on the M4A78T-E motherboard I'm using for the new build should be able to handle dual displays, as long as one is digital and one is analog (which is the display setup I normally run anyway, since I run the smaller of my two monitors through my old analog KVM).
If the world isn't making sense to you, you're either drinking too much or not drinking enough.