The option acpi_osi='Linux' works for Acer aspire 5738z + Ubuntu 10.4. For current release of Ubuntu 9.10 works options "nomodeset acpi_backlight=vendor"
The option acpi_osi='Linux' works for Acer aspire 5738z + Ubuntu 10.4. vendor"
For current release of Ubuntu 9.10 works options "nomodeset acpi_backlight=