Problem using QT in a plugin for Adobe After Effects (mac)

Hello,

While trying to port the AE plugin whose GUI uses QT, I've run into issues.
Windows version of plug-in works just fine. On Mac, right after I display a modal QDialog and then close it, I observe a strange behavior. Buttons in native AE windows start to not respond to mouse clicks.
For example, in Open Project dialog, I'm unable to select any items in the list, cannot press the Open button etc. This happens when using Cocoa version of QT 4.7. With Carbon version, the menu commands does not even work at all, i.e. I can select them but nothing happens. I've heard Qt installs its own event handler blocking the one set by the Host application. Setting Qt::AA_MacPluginApplication before creating the QApplication instance does not solve the problem. Could someone tell me what could be the cause of such behavior and suggest a possible workaround to this problem?

Thanks in advance