Ubuntu entry not working even if GRUB is correctly installed on target drive

[euthymos]

I've installed Ubuntu on a e-SATA HDD. I currently boot into it by pressing F8 at startup and accessing my motherboard's boot selection menu. GRUB is correctly installed (and working) on that HDD.
I would like to add an entry for this Ubuntu installation under Windows 7 bootloader which is installed on a RAID drive (obviously completely independent from the HDD where Ubuntu is installed).
I tried adding an entry for Ubuntu under Add/Remove Entries... I selected the correct partition, added the entry and rebooted. It does not work at all. If I choose "Ubuntu" entry under Windows 7 bootloader, I get an error message of some kinda loader like "operating system not found"...
What can I do to fix it?
Thanks in advance

 

[mqudsi]

Hi ethymos,

Download and install EasyBCD 2.0 from EasyBCD 2.0 Beta Builds - The NeoSmart Forums

Use it to add a new GRUB2 entry from EasyBCD and give that a shot.

 

[euthymos]

It works like a charm. Thank you!
Tell me if I can be useful in any way testing this beta

 

[mqudsi]

You're most welcome

Your confirmation that it worked is help enough!