I have the same problem, on a Medion notebook: Often, serial ports don't work. In these cases the error "ttyS0: LSR safety check engaged!" shows up in the kernel log, and I get "no souch device". This is pretty serious if you only have dialup.
** Tags added: modem regression serial ttys0 -- Serial ports of some HP Laptops don't work in Edgy https://launchpad.net/bugs/74034 -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
