Yeah. Using the past tense form instead of the past participle form is one of my pet peeves. It has been a marker for a less educated version of English since at least the time of Dickens. However, given that I'm now hearing it regularly (have came, have went, etc.) on news shows, I suspect that this is something that is changing in the English language. In the mean time, in WRITTEN English, it is a marker of a poor education. Definitely not something you want to teach ESL learners, and these courses are often used by non-native speakers to both learn a new language and to improve their English.