Hi,
This is happening as the Text caption, Rollover caption uses the same style as its default style. You can try creating a seperate style for the Rollover caption.
To do this,
1. Open Object Style manager.
2. Select 'RolloVer Caption' from Standard Objects>Rollover Caption, Click on the 'Clone' button
It Creates a new style with the name '[Default Caption Style]1
3. Click on the 'Set As Default' button.
This newly added style is set a s the Default for Rollover caption. Now wheneven you insert a Rollover caption, It gets inserted with the new Style and the Text caption gets inserted with the old style.
Hope this resolves the Issue.
Thanks,
Nimmy Sukumaran.