I know about this problem with Seditio on some hosts. It is usually solved by using POST parameters instead of GET, so can try this:

1. In your form add hidden fields:
Code:
<input type="hidden" name="a" value="newpoll" />
<input type="hidden" name="s" value="{POLL_NEWTOPIC_ID}" />


2. In plugin code change action and add a new tag:
Code:
"POLL_NEWTOPIC_SEND" => "plug.php?e=pagepolls",
'POLL_NEWTOPIC_ID' => $s,


3. Add POST import in the beginning of plugin's code, change:
Code:
$a = sed_import('a','G','ALP');
$s = sed_import('s','G','INT');

to
Code:
$a = sed_import('a','P','ALP');
$s = sed_import('s','P','INT');