All right, 'fess up: a number of you write your blog posts in some other program, e.g. OpenOffice Writer, and then cut and paste into the Roller edit window, right? And/or you grab text from other documents or web pages and paste that into Roller.
I can tell because your blog formatting is all over the place - a single post may change fonts several times, for no good reason.
It probably looked fine in the Roller edit window, which is not as WYSIWYG as it should be, and does not reflect all the formatting that will be imposed by the theme you're using in your blog. If a theme already uses small fonts (as many blog themes do, regardless of blogging platform, to my considerable irritation), and a <small> font setting is hidden in the formatting of the text you pasted, your text may become just about invisible when actually published on your blog.
One (tricky and tedious) way to fix this is to go into Roller's code view and remove all the <font> settings.
An easier way is to select ALL your text and paste it into a plain text editor (e.g., Windows Notepad), then copy it again from there and paste it into Roller. This clears all formatting, leaving you with plain ASCII text. Then use Roller's built-in tools to do whatever formatting you really need.
Caveat: This will also remove hyperlinks. The link text will still be there, but it will lose its linkiness.
Deirdré