Styles of course vary from version to version. So if you are running an old style on a new version of vBulletin you might see some small HTML/CSS/JavasScript problems. Especially, if template changes are included in the add-on style: this will adversely affect things after an upgrade which included template changes.
I am a bit concerned that you loaded your old styles back into the board. Have you done a comprehensive check on each template for rogue code? You would be much better off starting with a new style from a known source or restyling the standard vBulletin 4.2.2 style using stylevars.
I am glad to see you are making progress. Good job!