[boost] fruchterman_reingold.hpp graph layout locking up?

Hello, I am having a very weird error with the fruchterman_reingold.hpp file (from the most recent stable download 1.34.0, compiling under ubuntu 7.03) . When I run the fruchterman_reingold_force_directed_layout(...) function (after setting up the graph of course), the algorithm seems to sit on the first iterations. However, if I add a printf at ~line 111, printf("col: %d row:%d\n",columns,rows); things run fine. Any ideas? Best, -Dave