Cannot login as root, exited on signal 11

[Unga]

Hi all

This is FreeBSD 7.2 on i386.

After a custom compiled from sources installation, root cannot log in but normal users can log in.

Here are the messages in /var/log/messages:
Jun 14 00:44:58 xxx login: ROOT LOGIN (root) ON ttyv0
Jun 14 00:44:58 xxx kernel: pid 757 (login), uid 0: exited on signal 11
Jun 14 00:45:00 xxx kernel: pid 760 (cron), uid 0: exited on signal 11 (core dumped)

Note, cron also fails. 

When try to log in, it checks the password correctly, ie. if I type a wrong password for root, it says "Incorrect ...", but when type the correct password, it simply come out and prompts the login prompt.

It looks like something is missing required for the root to log in. I'm using bash shell. Any ideas? 

Many thanks in advance.

Best regards
Unga