boot-up stops just before login screen

[bamber]

I have reported this problem before but I cannot find it. I have ubuntu 12.04 on a dell inspiron 530.I have no other operating system. Lately, the boot-up stops, not every time, just before the login screen. I get a screen rather like the screen you see before shut-down but this time starting up processes.. Sample entries:
Speech-dispatcher disabled: edit/default/speech-dispatcher
Not starting udftools packet writing: No devices listed in /etc/default/udftools
* starting unstat daemon vnstald
*sane disabled /etc/default/saned
*starting Web server apache2
At the end there is blinking cursor. Pressing Enter takes me to the login screen. Once before the login screen appears but the final passwd box did not appear. On reboot it did.The listing on the black screen appears to be getting longer.Any help would be appreciated. I don't have constant broadband at home so my response to suggestions might be delayed.