I made a fix myselve. There were actually 2 errors in this line /scripts/postlist.inc.php

Line #921 was:

Code
$pageprint .= "<a href=\"{$config['BASE_URL']}/ubbthreads.php{$var_start}ubb{$var_eq}showflat{$var_sep}Post_ID{$var_eq}$Post_ID{$var_sep}page{$var_eq}$plink{$var_sep}fpart{$var_eq}$prints\">...</a> ";

and changed to:

Code
$pageprint .= "<a href=\"{$config['BASE_URL']}/ubbthreads.php{$var_start}ubb{$var_eq}showflat{$var_sep}Number{$var_eq}$Post_ID{$var_sep}page{$var_eq}$plink{$var_sep}fpart{$var_eq}$plink\">...</a> ";

Instead of adding the parameter Number it added to parameter Post_ID, that why it didn't find a matching post. And the fpart I think has to be the same as the page parameter.

On my board it now hops to a page somewhere in the middle.

[Linked Image from siemons.org]