How is the Portal Theme applied to a BSP?

Hi,

I have several BSP's that are displayed within the Portal (EP6 SP9).

Within the BSP's the datepicker does not work, if yo click on it nothing happens. If the BSP is executed outside the portal as a standalone app the datepicker does work. Therefore I assume that the error is related to the portal theme.

I have tried regenerating the ITS Theme (using sap_preview and sap_generate) but nothing seems to happen.

Should re-generating ITS Themes effect the display of a BSP within the Portal?

Is this issue likely to be with the ITS theme, with the Portal theme or something else entirely?

Many thanks,

Paul