Error type 2 is the major problem of all recent versions (1.8,1.9, 2.0). I sent the err.txt file to Adam Fisk (developer). Hope he will work it out.
Before that downloaded files were not identified with any program (including QuickTime) but finally self repaired after several desktop rebuildings.
Actually the best version (better working with my machine) is 1.8b. But still crushing with error 2 if I click the menue file of computer. I run 9.1 on iMac 500 mhz, 384 mb