It's started from /root/.profile. If Slim fails, you would see a text login, not get the normal system; is the file being correctly replaced?
Which version of TC, details about your setup?
Do you also see this on vanilla 2.0rc4, with only slim and it's dependencies loaded?
It is correctly replaced, but... /root/.profile needs to be added to /opt/.filetool.lst as well to make it persistent...
I am not seeing the SLiM login, but a text login. If I try to login as root at that text prompt, it tries starting up SLiM again, (as expected on further reflection) and returns me to the text login prompt.
Once logged in, on tc2.0rc3 and tc2.0rc4, things are fine.
As for details... I'm doing devel in qemu, using "-kernel bzImage -initrd tinycore.gz -hda /dev/sdb2" with append options "quiet syslog local=hda home=hda restore=hda user=rgb waitusb=15". /dev/sdb is a usb stick with 30MB ext3 first partition for /boot/ contents including kernel, initrd and extlinux bootloader, 500MB ext3 second partition for holding local, home and restore data. I'm doing testing on that usb stick, using sdb2 for local, home and restore in the extlinux config (and have also successfully used UUID to specify that partition). All this devel and testing is being done on x86 desktop and laptop hardware.
On my way to these conclusions, originally starting with a dirty data partition, I had various troubles including a black screen after X started up with icons across the bottom, but no right-click menu. I did see the SLiM login screen a couple of times, but can't reproduce those conditions. If I try to login as root, it attempts to run SLiM and re-presents me with a text login prompt.