Node Body empty after upgrade D6 > D7

I attempted an upgrade from 6.22 to 7.7 last night. Six hours later I declared defeat and restored my DB backup as the upgrade rendered my site useless. Why? Because none of the content in the Body showed up and I couldn't figure out how to display it. I looked at the nodes in edit mode and it was imminent, there was nothing stored in this new and "shining" body field.

I looked around the DB itself and as it turns out, the data was migrated, marked as node body, but just wasn't appearing. (don't ask me in what table the data was, it was one of the "field" ones, might have been "field_data_body" or something similar, but as I removed the install I can't remember the name.

I suspect that the reason for this result has something to do with the method of display I have in the 6.22 version. I'm not using teasers. The whole content of the Body text area is appearing on the front page and taxonomy listings and yet, the D7 install files might think that I'm only using teasers and not body. In a "normal" D6 body text area there's a "split summary at cursor" button above the Body text area. When I press the button all the data I've written in that body text area appears above the split - as if it all was the teaser.

I have searched the forums and issues for similar discussion and found amongst other things this bug report. That solution was committed to HEAD in November 2010, so it definitely should have been solved in the version I downloaded last Saturday. Meaning that even though the symptoms are similar, someone still needs to fix the bug as it appears in my upgrade.

The D6 system I tried to upgrade is a clean D6 install, setup in the spring 2010 although I can't remember which D6 install was the first one, I suspect it was ca. 6.15 given the dates of the archives I have in my collection. 6.15 was then updated to 6.19 and then finally 6.22 before I attempted the upgrade to D7.

Finally I must criticize the complete lack of mention of the fundamental changes in core in the Upgrade guidelines I thoroughly read before I attempted this upgrade. Proper information of the changes might have prepared me better for what was about to happen - where the flaws in a clean install (with almost NO contributed modules installed) might occur.