I found similar cases that UPLOAD update is lack of page_id. recentchange page
<rc type="log" ns="6" title="File:Siegelmarke Der Persönliche Adjutant Seiner Königlichen Hoheit des Prinzen Georg von Preussen W0204563.jpg" pageid="0" revid="0" old_revid="0"rcid="142847103" user="Nicolas Rück (WMDE)" oldlen="0" newlen="0" timestamp="2014-12-01T16:29:40Z" comment="[[Commons:GLAMwiki Toolset Project|GWToolset]]: Creating mediafile for Nicolas Rück (WMDE)." logid="103976391" logtype="upload" logaction="overwrite" img_sha1="swlwd4u41zhuaa0sq0x2pzuhzkr7xna" img_timestamp="2014-12-01T16:29:40Z"/>
<rc type="log" ns="6" title="File:Siegelmarke Glogau - Saganer Fürstenthums Landschaft W0204559.jpg" pageid="0" revid="0" old_revid="0" rcid="142847096" user="Nicolas Rück (WMDE)" oldlen="0" newlen="0" timestamp="2014-12-01T16:29:40Z" comment="[[Commons:GLAMwiki Toolset Project|GWToolset]]: Creating mediafile for Nicolas Rück (WMDE)."logid="103976394" logtype="upload" logaction="overwrite" img_sha1="3o7mqqobcibbnnwj8x166gmrxj5rbtb" img_timestamp="2014-12-01T16:29:40Z"/>
<rc type="log" ns="6" title="File:Siegelmarke Königlich Preussisches Haus - Archiv W0204564.jpg" pageid="0" revid="0" old_revid="0" rcid="142847109" user="Nicolas Rück (WMDE)"oldlen="0" newlen="0" timestamp="2014-12-01T16:29:40Z" comment="[[Commons:GLAMwiki Toolset Project|GWToolset]]: Creating mediafile for Nicolas Rück (WMDE)." logid="103976393"logtype="upload" logaction="overwrite" img_sha1="sx4uuswlcbh3itwrr4dy67u0s9ca18h" img_timestamp="2014-12-01T16:29:40Z"/>
It seems the lack of page_id problem only shows on logaction="overwrite" situation. Could you please take a look and see if this is a systematic bug?
Thanks,
Yijun