I posted in the simplest possible way: as rich text. The link was copied and pasted in from email, which meant it was a perfectly plain, undecorated chunk of text. The only thing I did was use the "size" selector among the buttons at the top of the "rich text" text box, to get it up to a size I could see (small.) Whatever mess it's made, it made without my assistance, and is due to the way LJ adds codes to incoming text. I didn't ask it to do that; I didn't tell it to do that. LJ did that.
It does not present a weird appearance on some computers. That alone should tell you it's not something that originated here, or that I can control.
Here's what we can do: every one of you who's had this problem, send a complaint in to LJ, so you can show them what it looks like on your computer. Tell them what your platform is (OS and browser.) Tell ME what your OS and browser are. LJ will need to know what OS/browser combinations are screwing up, and I'd like to know that too. Take a look at their recent news releases, to see if your browser is one of those that they commented on as having had a change in access.
When I know that the necessary complaints have been filed with LJ, and have been received (with at least one response) and when I know what OS/browser combinations are affected, I will try reposting. Understand that until LJ fixes whatever glitch they built into the system, there's no guarantee that anything I do will work, including deleting and reposting. My experience with reporting problems to LJ is dismal, because they do not reply in direct email to the person reporting the problem (sometimes someone else does, but usually you have to wade through one of their other groups to find out what they said.)
Nonetheless, since the only real cure for this is to have them fix their coding so that using the buttons they provide doesn't screw things up, this is the only procedure that might work. The problem needs to stay there, inconvenient as it is, until someone at LJ has seen it and diagnosed it--otherwise, they won't know what to fix. It should not be possible for someone posting to create the situation you're seeing unless fiddling with the formatting codes directly. I didn't. Therefore there's a glitch at the system level.
I am filing a help request with LJ at this time.