grub2 + 2 Linuxes + Windows xp (on 2 HDD)

[isfreaper]

Hello guys, please bear with me in explaining this odd and unprofessional context that my system is in.
Initially my pc had a 40 GB HDD and and I'd installed a windows xp on the this drive; after some time this 40 GB HDD was removed and an Ubuntu 10.4 was install on 60 GB HDD by someone else. Because now we are both working on this PC the 40 GB HDD was reinserted and the booting was made by choosing the desired HDD from BIOS's boot menu. And to complicate things even more I've install an Linux Mint 9 on my 40 GB HDD so now the PC have a 40 GB HDD (with Windows XP and Linux Mint 9 ) and a 60 GB (with Linux Ubuntu 10.4) the grub2 was updated on Mint and installed on the 40 GB MBR so now all 3 OS are bootable and working fine.
My question is how to keep the above configuration from being overwritten by the ubuntu in an eventual update-grub from ubuntu's system w/ kernel update. Maybe a grub uninstall from ubuntu?
I know the above configuration isn't elegant by far but it cannot be changed and I'm stuck with it.
Any ideas or suggestions will be most welcomed.

Thank you for your time

[markcynt]

If Mint is controlling Grub Ubuntu won't change anything unless you tell it to.

Edit: As a matter of fact update-grub won't hurt anything no matter which Linux out of the two is controlling Grub.

You may need to run update-grub manually after a kernel update but that's no big deal.

[isfreaper]

THX for the quick answer, the fact was that I have only 10-15 minutes of testing with full (root) access to both distributions every 2 days, so no time of debugging if something were to go wrong but it will be no problem if ubuntu/mint will keep everything working with maybe some inverting in the boot order.

LE: All worked fine because when update-grub is performed from ubuntu it's updating (with all 3 OS) the MBR from the second HDD (60 GB) and the whole system boots from the other HDD; Well this is a bonus: if something wrong happens whit the "Mint's" grub I'll just invert the HDD on the motherboard primary<-> secondary and will be up and running