I have came across this problem lately in one of the wordpress theme SevenMag.
I searched for a long hours of time and was not able to beat it. The wp-pagenavi function was inside the theme and I was not using as a plugin.
I tried installing the plugin instead hoping that it will work and tried to make the default wp-pagenavi option to disable.
But I couldn’t get luck on that either. My problem was the pagination error on home page only that I was clicking the Page 2, 3, 4, … it still returned me Page 1.
So I got through this solution of code.
I replaced all the
query_posts('cat=10');
or if you have any other form like
query_posts( array( 'cat' => 10 ) );
Just change it to
query_posts( array( 'cat' => 10, 'paged' => get_query_var('paged') ) );
If that doesn’t work try
query_posts( array( 'cat' => 10, 'paged' => get_query_var('page') ) );
The bottom line is just replace
‘paged’ Key Value to get_query_var(‘paged’) or get_query_var(‘page’) which ever suits your case in the PHP files where ever your theme have included it.
In my case it was 3 files page.php, pagination-blank.php, pagination-slideshow.php
And you might get a working pagination with WP-PageNavi.