Hiya Skywalker,
You truly need to choose one way or the other with the HTML Editor. This really does cause serious problems to your code and isn't intended to be used that way. I realize you are aware of the problem now at least, but why not give VSD a look over and see how that would work for you? You can do that for 30 days free which gives you plenty of time to get the hang of how it works and see if it's what would help you better.
The reason I really try to stress this issue is because image placing is one of the things that the swapping totally screws up among many other things. There is no stable code at all when you do this as it will keep swapping it's code back and forth all the time each time you swap. I guess I just can't stress enough the problems that the swap causes and that it's most likely most of your difficulties trying to place your images correctly. If you've swapped back and forth on that page already a few times, it could just be that the code is pretty messed up now and it literally "can't" place the image correctly because it's mixed up and trying to follow too many styles and settings set between 2 different coding styles.
Hopefully that makes sense lol, I can't force you of course to change, but I can surely stress the importance of what's happening and hopefully help you understand why you're most likely having difficulties.
As for the how to, I would try the help file to see if there are any helps in there for it, other than that a Google search for html image position should find you lots of help. Of course the problem will be that you need to know how it's done in the code that it will be in after you're done. In other words, if you plan to end it all in Code setting, then look for the HTML code for it, if you plan to end it all on the Visual side, then you'll need to know the positionining code for that style which I have no clue on lol. That's the main dilemma with the swapping.
Just so you know also, VSD does give you a way to enter HTML, FLASH, JAVA etc. code in it so you can do so without messing up your code like the HTML Editor will. Gives you a lot of versatility without all the headaches that the code changing will give you.
P.S.S. The down side of going with VSD is that you would have to restart your site in VSD as it doesn't edit already made sites as it has it's own built in file system and cannot import files to it. But once done, then you just go from there so although it would be restarting with a setback, it would be moving on with much more productivity