Please, accept my sincere apologies for the misunderstanding. I suggest to upgrade to the latest version of RadControls, Q12008, SP2, namely 2008.1 619 in case you are not using it. After that, you can achieve the desired behavior by adding the following CSS style, in order to override the RadToolTip's z-index:
| z-index: 4999 !important;
Please, note that you should use the RadToolTip's ClientID in order to apply the setting correctly.
In case you are using the RadToolTipManager
control, you can set the proper z-index by using its style
attribute as explained here
All the best,
the Telerik team