Version:           1.3.0_devel (using KDE 3.4.0, compiled sources)
Compiler:          gcc version 3.4.3
OS:                SunOS (sun4u) release 5.8

We have problems with kst from HEAD (I don't know since when this is the case), but some files won't load. I unfortunately can't send you the actual file it happens with (I could send the .kst, but the data file is more problematic) but at some point during the initial document loading, kst UI freezes while the only output I get in the console is "update thread paused".

Below is a backtrace I got from the debugger. I hope that's enough to locate the problem, as it is really blocking: we can't work on saved files (it happens indifferently with files saved recently or long ago). 
FYI, we have the same problem with two different datasources, while both datafiles are read correctly from the datawizard. The common point between both cases is that we use equations, though, and looking at the backtrace it seems to be linked. I suspect there's something wrong with equations, but I don't have time right now to dig more...

Program received signal SIGINT, Interrupt.
KstVector::internalUpdate (this=0xb5f630, providerRC=KstObject::UPDATE) at kstvector.cpp:378
  /dk/ouvea-3510-0/users/brisset/graphics/kst/src/libkst/kstvector.cpp:378:10734:beg:0xfed3fe2c
(gdb) where
#0  KstVector::internalUpdate (this=0xb5f630, providerRC=KstObject::UPDATE) at kstvector.cpp:378
#1  0xfed449cc in KstRVector::doUpdate (this=0xb5f630, force=false) at kstrvector.cpp:627
#2  0xfed44a60 in KstRVector::update (this=0xb5f630, update_counter=0) at kstrvector.cpp:420
#3  0xfede7d80 in Equation::Data::update (this=0xc7bff0, counter=-1, ctx=0xffbeb258) at enodes.cpp:896
#4  0xfede53c0 in Equation::BinaryNode::update (this=0xc7caa8, counter=-1, ctx=0xffbeb258) at enodes.cpp:160
#5  0xfede53dc in Equation::BinaryNode::update (this=0xc7cac0, counter=-1, ctx=0xffbeb258) at enodes.cpp:161
#6  0xfede53c0 in Equation::BinaryNode::update (this=0xc7cc40, counter=-1, ctx=0xffbeb258) at enodes.cpp:160
#7  0xfede53dc in Equation::BinaryNode::update (this=0xc7cc58, counter=-1, ctx=0xffbeb258) at enodes.cpp:161
#8  0xfede53dc in Equation::BinaryNode::update (this=0xc7cc70, counter=-1, ctx=0xffbeb258) at enodes.cpp:161
#9  0xfedd4740 in KstEquation::setEquation (this=0xc757c8, in_fn=@0xffbeb448) at kstequation.cpp:284
#10 0xfedd5838 in KstEquation::commonConstructor (this=0xc757c8, in_tag=@0xffbeb450, in_equation=@0xffbeb448) at kstequation.cpp:162
#11 0xfedd6860 in KstEquation (this=0xc757c8, e=@0xffbeb3e0) at kstequation.cpp:138
#12 0xff1b02b4 in KstDoc::openDocument (this=0x17b708, url=@0xffbeb918, o_file=@0x55a5c4, o_n=-2, o_f=-2, o_s=-1, o_ave=false) at kstdoc.cpp:404
#13 0xff1c2e20 in KstApp::openDocumentFile (this=0x11fc18, in_filename=@0x55a5c0, o_file=@0x55a5c4, o_n=-2, o_f=-2, o_s=-1, o_ave=false, delayed=false) at kst.cpp:1031
#14 0xff1c2ff8 in KstApp::doDelayedOpens (this=0x11fc18) at kst.cpp:997
#15 0xff1c6340 in KstApp::qt_invoke (this=0x11fc18, _id=251, _o=0xffbebb68) at kst.moc:641
#16 0xfd69c5c4 in QObject::activate_signal () from /usr/local/kde/lib/libqt-mt.so.3
#17 0xfd99dae0 in QSignal::signal () from /usr/local/kde/lib/libqt-mt.so.3
#18 0xfd6b2de4 in QSignal::activate () from /usr/local/kde/lib/libqt-mt.so.3
#19 0xfd6ba54c in QSingleShotTimer::event () from /usr/local/kde/lib/libqt-mt.so.3
#20 0xfd643024 in QApplication::internalNotify () from /usr/local/kde/lib/libqt-mt.so.3
#21 0xfd6432f0 in QApplication::notify () from /usr/local/kde/lib/libqt-mt.so.3
#22 0xfe0bd6d0 in KApplication::notify () from /usr/local/kde/V3.4.0/lib/libkdecore.so.4
#23 0xfd636a6c in QEventLoop::activateTimers () from /usr/local/kde/lib/libqt-mt.so.3
#24 0xfd5f24e4 in QEventLoop::processEvents () from /usr/local/kde/lib/libqt-mt.so.3
#25 0xfd658e7c in QEventLoop::enterLoop () from /usr/local/kde/lib/libqt-mt.so.3
#26 0xfd658d64 in QEventLoop::exec () from /usr/local/kde/lib/libqt-mt.so.3
#27 0xfd641fb8 in QApplication::exec () from /usr/local/kde/lib/libqt-mt.so.3
#28 0x0001f384 in main ()
(