Acronis Disk Director Suite 10 - problem merging partitions

[spacewalk]

Hi,
I am using the french version of Acronis Disk Director Suite 10.0. My PC came with VISTA pre-installed. I have kept VISTA and added XP with a dual boot. So far so good. There was a partition for recovery with VISTA. Hence I got 3 partitions: C:/ for VISTA, D:/ for XP and another with "recovery system". Under XP, I have deleted the "Recovery System" partition to free up some space for my XP partition. I got then a "non-allocated" space that I have later converted in a partition (NTFS). When trying to merge this partition with the XP partition, I get the following error message "E000A0460: Impossible de fusionner les partitions" (sorry, the error message is in French !).

Am I following the right method in order to increase the XP partition (D:/) ? If not what is the right way to do it then ?
Thank you for your help.

[MudCrab]

Was the unallocated space next to the D: (XP) partition? If it is, I would just delete the "converted" partition in that space and then resize the XP partition to use the space.

If you're starting the procedure in Windows, you may have better success booting from the DD CD and trying it.

[spacewalk]

Thank you MudCrab for your reply. So far no success. I have tried also your suggestion booting from the DD CD and it did not work.
I have made a couple of changes and have now 2 adjacent partitions; G: and D:. I would like to use the free space of G: (about 9 Gb) to increase size of D:. When using increase size of D: from G:, I get a error message stating I have exceeded maximum size ?
I have also found out that the D: partition has a red "C" mark. I do not know what this means.
I have attached a screen cpature of the Acronis screen.
Thank you again for trying helping me. I appreciate.