I assume I clciked your username and it wasn't linked to a free hosted WordPress.com blog. If I made a mistake then I do apologize.
You refer to installing the Sunspot theme and yet the blog linked to your username and the pone you posted the link to is wearing The Morning After theme. That theme displays only the most recent post on the front page. It has many customizable fetures so if it's The Morning After Theme and and not Sunspot that you are referring to please read the article I linked to.
Can someone fix this pagination problem I explained in the first post?
Yes. Staff have introduced “infinite scroll” to some themes and will be implementing it on all themes that have a suitable structure for infinite scroll. This is a site wide change.
If you have a theme with footer widgets (not Sunspot) you can use a workaround to regain control over how many posts are displayed on the front page of your blog. If you have a theme with footer widgets all you need to do is install an empty text widget into any footer area for widgets. When you do that there will be an option displayed on this pgae > Settings > Reading to disable infinite scroll. Once you have done that your number of posts set on that same Reading page will prevail.
For some other theme possibilities see here > http://en.forums.wordpress.com/topic/of-posts-displayed-on-front-page?replies=21#post-842402
If you are referring to Sunspot these may be helpful links:
Sunspot theme desciption
Sunspot live demo site