I get the same results with the SVN Trunk live CD releases. The primary release (setup/install) versions boot okay.
Looking back I see that the liveCD boot loader method was changed around mid-summer last year. My guess is that something has gone amiss with the boot loader. One of the other developers has already confirmed in another thread that theres a known issue with the current dev ISO live versions regarding the bootloader.
This was the reason why I suggested that boot loading info isn't restricted to debug info but is made officially and permanently "present" even on final releases at least to confirm the primary boot stages. Or hidden by the logo but with a visible key hint onscreen such as "Press TAB or ESC to view boot sequence" This would save a lot of faffing about, developer time and quite a few posts to the forum if the exact point of lockup could be confirmed without having to recompile. Maybe even a MS style F8 single step key press at bootup so we can see whats happening?
I've tried all recent SVN trunk liveCD ISOs including DBG and REL and none display any text or debugging output but just do what you've described in terms of locking up solid at the atom logo with no progress indication on the progress bar.
Not a complaint - just trying to point the coders in the right direction as best I can without more info! Ive done a bit of coding and I now its madly frustrating not to have accurate info and know where to start looking in the codebase for problems!.
If anyone else is interested I note in the setup/install ROS versions under QEMU that volumes created with recent FILEDISK show silly (high) numbers of sectors/free space on the partitioning screen (didn't write down but figures in the range of terabytes for a 300mb filedisk volume - poss due to the Bochs BIOS in qemu?)
Coming from a background in professional IT support I can't stress too strongly how important accurate and relevant visual output is in getting a product accepted and adopted by people. Pretty logos are less important than text info. The Microsoft boot-control/ bootlog.txt menu keys were a quantum-leap when introduced in the mid-1990s and saved a huge amount of time and money in support costs!!