As a frequent user here on pixelation, and on pixeljoint, I guess I have to give my 2 pesos:
To be honest, I've never had any issues with a member asking for help here or on the pj forums. I can also say that I've NEVER noticed a direct correlation between users submitted wips here at Pixelation for pj competitions and the people who win. I have noticed, however, that the winners of the competitions, are usually frequent Pixelation users, or frequent pj posters, who have developed some great skills over the years. That just goes along with the territory of practice makes perfect. As far as any one who's used a piece directly edited by a member here, you can either report it to the mods and admins at PJ, or even me if you wish, and we'll review what's going on. Getting help is one thing, but using rips and edits is intolerable in my opinion. I'm still kinda' iffy about allowing linearts in pj, to be honest, as I only want people to birth original ideas, and not develop problems another user has.(like a constant cancer that can't be stopped, due to a low excuse of "style" to hide behind)
I'm in agreement over keeping these websites in "friendly separation" mode, as they are two different beasts all together. (none better than the other, just different) And I don't think hindering the amount of help users offer will make matters any better. Yes, the user base here does seem to have some great talent, and critique, but that's mainly due to it's small user base of active members, while PJ has a larger user base, making it difficult to focus some great attention or critique towards some of the people who ask for it. Either way, competition is a great motivator for young artistic minds, willing to improve. Ever since pj competitions began, the amount of submitted art, and quality of certain users has improved GREATLY, in my humble opinion.
So again, Ilkke, if you feel a user's edited piece was directly taken in vain without permission, contact or advise the square heads of the round table(pj admins and mods) and we will deal with it accordingly...just my opinion.

*I hope this thread was ok to respond to, don't mean to reopen any dead topic or anything...