WordPress re-formatting/undoing my formatting!

I started my blog on June 19th, and ever since WP has been a lot of trouble. I’ve been trying to ignore it but it’s really starting to get aggravating.

– After my first couple of posts, WP decided that it liked my past three or so posts all in bold face.

– Nearly every time I post, WP undoes my formatting. For example, after saving or publishing, it will ignore page breaks as if I never entered them.

I wrote a long post tonight where many page breaks, and blocks of italics were used. WP ignored several of the breaks, and also added parts into italics that were not meant to be that way.

Here are some other details that might be helpful:

– I’m using a template that I downloaded from another site and modified. I have a feeling these problems might have something to do with the template, I’m not sure if it would be from the original template or if I somehow made a mistake while I edited it, although I’m not a newbie when it comes to modifying templates.

– I haven’t made any significant changes to it other than changing the color, logo, and adding a few sidebars.

Any suggestions?