UPDATE
I have reverted back to Jquery 1.3.2 and everything is working, not sure what the problem is/was as I have not changed anything else apart of t
I have been similar problems. It would launch once and not a 2nd time under different tabs. I used a class instead of an id, and used the same class name everywhere. To me it appears datepicker activates once and the original initialization has to be used everywhere. One can probably code around this with the destroy api, but for me it was easy to simply use the same class everywhere.