[jQuery] jqModal caching ajax requests

[jQuery] jqModal caching ajax requests

Hello,
I am using ajax requests to populate a jqModal window. The problem is that the content I am loading in the window gets cached, so any future requests will return the cached content.
For example, I have:
$('#popupwin').jqm({ajax: 'popup.php?win=add'}).jqmShow();
This will insert content A in my window.
Later on (the window gets closed in the meantime) I want to make another ajax request, for inserting content B in the jqModal window.
$('#popupwin').jqm({ajax: 'popup.php?win=view}).jqmShow();
Surprise, I get content A again, instead of content B.
The script wich i'm using to generate the content is functioning properly, so is surely a cache issue.
I tried:
$('#popupwin').jqm({ajax: 'popup.php?win=view&imgid=' + id + '&ms=' + ms}).jqmShow();
to overcome the cache, still with no result.
Any idea on how to solve this?
Thank you so much.
Emanuel