We're using jGenerator for the Pachyderm project - to replace the abandoned Macromedia Generator product - for wrapping images in .swf files for display within Pachyderm presentations. The .swf files provide value-add stuff like "tombstone" data, and a lightweight, unobtrusive form of DRM.
However, jGenerator has been rather neglected for 3 years now, and as a result it's starting to show cobwebs etc... Remember my friend Murphy? Largely a result of these cobwebs.
Today, days after we thought we nuked the jGenerator problem, it came back in full force. Building presentations would occasionally hang (sometimes not reliably, or sometimes very reliably). We tracked down the problem thanks to the handy dandy java debugger jdb (handy document on using jdb in a running WebObjects app), and it was the result of jGenerator using java.awt.Rectangle classes rather than java.awt.geom.Rectangle2D.
The methods had been altered to use Rectangle2D in the signatures, but were actually passing around Rectangle objects instead. This apparently causes problems on MacOSX and other Unix-like systems, as was discovered by the OpenLaszlo folks. They had to start their own fork of jGenerator 2.2 to fix this (and potentially other) problems. We just did the same.
We had another round of Team Programming at a Distance - the three of us brainstorming and hacking and researching. That is soooo much more fun and rewarding than copying and pasting...