Problem with displaying pictures after uploading

After changing a server and database I got problems with displaying pictures after uploading them.
I think there is something wrong with URL address. Before I changed the server pictures in HTML were displaying this way:

<!--
<a rel="attachment wp-att-3418">href="http://powrotnik.eu/index.php/powrotnik-eu-ma-rok/one-year/"><img class="alignnone size-full wp-image-3418" title="One-year" src="http://powrotnik.eu/wp-content/uploads/2011/12/One-year.jpg" alt="" width="520" height="390" /></a>
-->

now like that:

<!--
<a>href="http://powrotnik.eu/?attachment_id=3436" rel="attachment wp-att-3436"><img class="alignnone size-full wp-image-3436" title="2012" src="http://powrotnik.eu/wp-content/uploads/2012/01/2012.jpg" alt="" width="600" height="456" /></a>
-->

What can I do to fix it? Could you help me please?

Lukasz

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