Well... Some days ago I've started to make anything to install CTM. I have two TrueCrypt partitions and Linux in another (Kubuntu 10.04). The CTM installer was blocked three times:
1. Multiply devices (or disks, I can't remember, although I'm in a notebook with just one harddisk...).
2. Truecrypt installed.
3. And then Linux is detected in the last partition...
How I manage it:
1. Remove attached devices... although does not seem to be a problem.
2. Uninstalled Truecrypt but does not boot.
3. Hide Linux and Truecrypt partitions with a partition manager tool.
4. Install CTM successfully.
1. First I got a BSOD (probably the conflict with Truecrypt driver? 0x0000007B (0x80786B58, 0xC0000034, 0x00000000, 0x00000000).
2. Uninistalled CTM by the console.
3. Windows 7 boots normally and CTM finished the uninstallation.
Installing CTM again and booting worked without a BSOD.
Then I could install Truecrypt, it worked and does not conflict. I'm not protecting the TrueCrypt partitions into CTM, of course.
Tried to boot Linux in the hidden partition formated as Ext4 (using the Windows 7 boot loader + EasyBCD) I found the following:
1. Kubuntu entry in Windows 7 boot loader (/dev/sda9 or (hd0,8)) fails (file not found).
2. Kubuntu grubless in Windows 7 boot loader works, but I can't boot the normal way, just the Recovery Mode.
I'm not sure if the problem is being the partition hidden or there is any problem in Linux (as I'm not an expert with Linux).
So, I'm not sure it's a dangerous situation but you could have Linux as a second OS
(if it was installed before CTM and probably using Windows 7 boot loader with GRUB not installed in the master) and TrueCrypt
(if it is installed after CTM and with its partitions not protected by CTM).
Happy CTM user