Sure, they crash (or do something funny) a lot of time, but that's the problem with these ActiveX controls. If you buy anything from a Korean site you end up with an unknown number of plugins downloaded from everywhere, so how do we know if it's a bug in some plugin, a plugin already infected with virus, or just some malware you downloaded accidentally? (The last one, because you have to hit "OK" all the time: actually recent versions of Windows is being quite reasonable and wants to warn you when you install binaries from random websites, but this is exactly what Koreans are asked to do every day, so Korean bank websites contain these helpful pages showing how to lower Windows' "security level" and override the warnings.)