I don't mean to offend you, but I must ask, are you running a pirate copy or one that you downloaded from Amanita's server?
If it's the former you can check
here to confirm that the checksums of the version you downloaded are correct.
If it's the latter I assure you that someone from Amanita will reply to your post within a day or two.
No offense taken. It's a legitimate copy that I paid $20 for and downloaded from Amanita's server.
I just went and checked the MD5 checksum of the file I downloaded, and it's correct.
FOLLOW-UP EDIT: I tried installing the game from the same burned disk on my older machine, a 2 GHz Athlon desktop with 2 GB RAM. Inexplicably (to me anyway), it installed perfectly on that one and seems to run fine. No idea why Machinarium doesn't like my dual-boot laptop, which is actually a more powerful machine.