I moved my perfectly working cart with calendar module to a new server and the entire site crashed. I couldn't get into admin and on the home page the calendar module disappeared.
The problem was actually fairly straightforward - the comments were being delineated with // instead of /** and */ . I changed each of the files and it now seems to be working.
I also had the above table headings problems until I removed the comment.
This is a really nice module and does work perfectly. It works fine on a windows server without the change.
I did have to fiddle quite a lot with the iframe and the CSS. Have a look at
www.grandifloradirect.co.za