Entry method not found in QtCore4.dll after compiling

Hi, I just compiled Qt4.8 with the latest MinGW (the same that I use for compiling my Qt+Ogre program). The application is compiling fine but when I launch it, I have the message telling that the entry point of the method ?cap@QRegExp@@QAE?AVQString@@H@Z is unreachable in the QtCore4.dll library. Here is the original french message: Le point d’entrée de procédure ?cap@QRegExp@@QAE?AVQString@@H@Z est introuvable dans la bibliothèque de liaisons dynamique QtCore4.dll I used the .dll stored in qt-everywhere…/bin/. I copied this dll in the same directory as my application. I had the same message when I used the prebuilt version of Qt4.8. I know this topic exist already but I did all that was mentionned (compiled Qt with the same MinGW used for compiling the application, copy the right dll (?)). By the way, I have matlab directory in my PATH with QtCore.dll. Is the PATH taken in prior than the current directory? Many thanks in advance!