Bob,
I use Boot Manager to run two eCS opsystems and a Linux one. I run the eCS partitions as normal and I set up Linux from a disk and when it came to setting up Grub, it asked where I wanted Grub, in its own partition or in the Linux base partition. I asked for it to be in the Linux partition and it continued the install.
I put an entry in BM pointing at the Linux partition and use it to start Linux. The machine jumps to the Grub start up, asks me which kernel I wish to use and carries on from there.
So, put Grub in the Linux partition, it works for me

cheers, Bill