As I recall,the problem described by Sal can occur because of low screen resolution. the size of the pop-up window is set in one of the integration files, but in that case a) the demo run from your server should work fine, b) you will not see portions of the DragMath app when invoked within htmlarea.
Pablo does not indicate whether he tried the demo, and it is unclear to me that he is not seeing all the dragmath window (and since their is an illustration in the docs, stating that the windows does not appear as in the docs, or that ony a portion of the window as appears in the docs windows would be a dead give-away, but is not something that Pablo seems to note.