Permalinks problem

Hello !

I’m having a strange problem with permalinks 😉 when i use %postname% or %post_id% as a structure of my permalinks on the main page of my store the “next page” displays nothing found.

But when i go into any category it works fine, only the main page doesnt work.
However, If i use the defoult permalinks such as “http://raskon.pl/?p=123”
The whole website is working fine 😉

Ive been trying to change a little of httcaccess file but i dont know how 😉 First time doing this. My .httc looks that

# BEGIN WordPress
<IfModule mod_rewrite.c>
RewriteEngine On
RewriteBase /
RewriteRule ^index\.php$ – [L]
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule . /index.php [L]
</IfModule>

# END WordPress

Could you help me 😉 ? Oh and the website is http://www.raskon.pl/sklep