Whenever I get a crazy result after an install, I figure my install cdrom is bad and try another. About half the time that fixes the problem. However, I don't think I have ever tried to install it on an Acer. I generally install Vector 5.9 on old hardware.
If that doesn't work, I try, as indicated, the Vesa driver (boot to tui and then vasm as root). (or, if I'm already in the gui, init 2 from root for the vasm change then init 4 to see if it works). that works about 20% of the time.
If that (install with a new disk and Vesa) doesn't work, I change the partitions from 3 (swap, boot and home) to two (swap and boot). That works about 5% of the time.
If that doesn't work, I use the computer for target practice.