If it's the same name as your HN username, I don't see any obvious way to mispronounce it, other than whether the first 'o' is long or short. Is that the bit people mispronounce?
My Polish friends tell me that speaking in Polish "ow" is pronounced like the English word "off" (or maybe "of"? I forget) instead of the English word "ow". So "off-ski" or "uv-ski" instead of "ow-ski", at least for some of them.
This is pretty close to what happens. It's generally phonetic, and yet there seems to be a wide variety of first pronunciations, which deviate from the phonetic by several syllables either way.