I am facing this intermittent issue. Sometimes, on UI, the buttons on an applet show the control "name" instead of "caption". When I log off and log in again, the button shows control "caption" on it properly.
For e.g. Button Caption is "Reply", but on applet it is displayed as "ButtonReply" which is the name of the control. After re-login, the button is displayed as "Reply".
Just a quick check,
1)Have you tried re-compiling the applet again?
2)Delete your HI interactivity and then reinstall again?
3) Play around with your IE resolution with youre mouse wheel?Sometimes this might be the cause.