FYI: Your images are a little funny. Normally, you click on a thumbnail and it gets larger and more clear, but yours go dark.

camilo umaña wrote:

 

In the first image an undesired rule appears at the end of the column.

I'm not sure why that's there.

camilo umaña wrote:

In the second image, when the following text goes to next page the situation is different. No rule. Although the footnote is placed to the right, that is not good at all. Conclusion? a footnote at the END of a splitted column behaves in different manners depending in something not exactly associated as it is the following text!

The footnote will appear at the end of the text frame (or column) that holds the cited text, so just from the way your screenshot looks, I'd say that the page has either a two-column frame, or two connected frames, like you would get if you auto-flowed text into a page with two-column margins. I'm not sure if there is a way to make the footnote appear on the left side of the page if the citation is in the right column.

camilo umaña wrote:

 

In the third image just a maremagnum is present. Footnote numbering is erroneous. Also position.

The rule in your third screenshot extends beyond the page. Can you give a screenshot of the Layout tab of your Footnote Options pallet?

I had a thought that the width of the rule might be causing the line to extend off the page in your third screenshot, and that's why I wanted to see your Footnote Options pallet. While 300 points seems like it may have been the cause, I can't get the line to extend past the text frame on my copy of CS3. I don't know if it works differently on your version, but I suspect I just guessed wrong this time. Sorry.