I've made investigation regarding condition at line 555 in KWTextDocumentLayout.cpp:
bottomOfText > m_state->shape->size().height() && document()->blockCount() == 1
I've found a real problem, which can by very simply shown. Open KWork -> change font size to 72 -> hold on wrining 'A' till you come to second page. Than Kword starts to loop. Why ? Because mentioned condition is true. We have one block and we'd like to go on second page. There's return after that condition and kword than do the same in loop to infinity. You now that it's basic functionality, which should works well.
I suggest one of two options:
1. remove condition. Collect problematic files by testers and do investigation. Than make solution.
2. add one more check to condition: if frame is header or footer. This block was added to resize header or footer size. That can be show via svn blame and comment in commit.
Second option is my patch.