Here are the known issues when running Invision 3515 August'07 Release with mIRC 6.3 (they aren't found if you use mIRC 6.21). They will be cleared up in the September release.
* Buttons are missing if you use the Invision toolbar buttons rather than mIRC's toolbar buttons. If you want the updated buttons file prior to the September release, let me know and I'll send it to you. Otherwise, just use mIRC's buttons until the next release.
* mIRC 6.3 has new options in the mIRC.ini file. This means that various things are turned on that were off before. This will be changed for the next release. Of course, you can always just change the settings in mIRC yourself.
* The 3 checkboxes for the new traytips in Main Settings > Additional Settings are too close together. They will be adjusted for the next release.