Boot failed after upgrade to 11.10

[leonidas300]

I did an upgrade from 11.04 to 11.10 but after that my laptop failed to boot. I get loop errors like:

ata1.00: status: { DRDY }
ata1.00: error: { UNC }

res 51/40:03:7d:57:41/00:00:00:00:00:/e5 Emask 0x9 (media error)

end_request: I/O error, dev sda, sector 88168317

So what's going wrong? How can I fix it.

Some information about my laptop:
Ubuntu 11.10 oneiric 32bit (en_US.UTF-8),
AMD Athlon 64 Processor 3400+ ‖ RAM 1254 MiB ‖ Acer Aspire 1520
nVidia NV36 [GeForce FX Go5700] [10de:0347] (rev a1)
eth0: Realtek RTL-8169 Gigabit Ethernet [10ec:8169] (rev 10)