Version:            (using KDE KDE 3.5.6)
Installed from:    Gentoo Packages
Compiler:          gcc (GCC) 4.1.1 (Gentoo 4.1.1-r3) 
OS:                Linux

If I open a file with a "php" extension that contains a "<?" at the beginning, KWrite simply freezes. Same happens if I save an empty file with s "php" extension, and then type "<?", etc.

Some backtraces I see in GDB:

#0  0xb74eb219 in QRegExpEngine::matchHere () from /usr/qt/3/lib/libqt-mt.so.3
#1  0xb74ebb8a in QRegExpEngine::match () from /usr/qt/3/lib/libqt-mt.so.3
#2  0xb74eee70 in QRegExp::search () from /usr/qt/3/lib/libqt-mt.so.3
#3  0xb63c9ff8 in ?? () from /usr/kde/3.5/lib/kde3/libkatepart.so
#4  0x082ac528 in ?? ()
#5  0x084e98c8 in ?? ()
#6  0x00000000 in ?? ()

Or this:

#0  0xb7156e2a in ?? () from /usr/qt/3/lib/libqt-mt.so.3
#1  0xb74f33fc in QString::operator= () from /usr/qt/3/lib/libqt-mt.so.3
#2  0xb74eec47 in QRegExp::prepareEngineForMatch () from /usr/qt/3/lib/libqt-mt.so.3
#3  0xb74eee1f in QRegExp::search () from /usr/qt/3/lib/libqt-mt.so.3
#4  0xb63c9ff8 in ?? () from /usr/kde/3.5/lib/kde3/libkatepart.so
#5  0x0862dcd8 in ?? ()
#6  0x085ffc48 in ?? ()
#7  0x00000000 in ?? ()

Also, I tried this in Ubuntu - and KWrite worked fine there...

But - the same problem happens in KDE4, compiled from SVN sources. I'll attach a huge backtrace.