Excerpt Function problem

I was using Inline Ajax Post Plugin to display, excerpt. But now I have disable this plugin, as it doesn’t show complete Post footer.

Now, I want to disable this plugin to use normal WordPress excerpt function. But I am facing following problem:

1. If I disable inap plugin and use <php? the_excerpt():?>, the post.php doesn’t display posts on main page.

2. If I keep inap activated, and use <php? the_excerpt():?>, it displays the posts as excerpt, but it doesn’t display “Continue reading” etc. message or link to continue reading post.

I have tried to use un-edited post.php also, but the problem remain same.

Can anyone here, advice me the cause of the error?