QUOTE(pandy @ Oct 6 2009, 01:30 AM)

That may be what you enter, but it isn't the output. So Darin was right.
View Source and see for yourself.
HTML
<p>
<p>
<img src="images/dog1.jpg" alt="A dog"><br />
<img src="images/pelusa.jpg" alt="Another dog"><br />
<img src="images/puppies.jpg" alt="The puppies"></p>
</p>
I guess you enter your code in an online editor. Maybe it adds a BR every time you hit ENTER and a P when you do it twice. Try to put everything on one single line and see if that helps.
Checking the source I found this:
<p>
<img src="images/dog1.jpg" alt="A dog"><br />
<img src="images/pelusa.jpg" alt="Another dog"><br />
<img src="images/puppies.jpg" alt="The puppies"></p>
As you say it adds a br tag, doesn't it?
When you write a post on wordpress you have to views on the editor to check what you are writing: a VISUAL view and a HTML view. On the VISUAL view you see the three images in this case, and on the HTML view you see the code. The confusing thing is when I see the HTML view the code doesn't show a BR tag at the end of each image AND when I see the SOURCE on my explorer, appear the code above that present a BR at the end of each image inserted. That is confusing for me Why doesn't show the BR tags on the HTML view of the editor for you to know that they are there and to know that images are going to line up vertically not horizontally as I wanted to show them.
THXS