This is a shot in the dark, but if there's anybody using Xerces-C that might have some experience with the DTD implementation in it, or that has a real need for it to work well, a lot of the recent bugs coming in are connected to the DTD parsing code. I'm currently the person with the bandwidth and enough need to be trying to fix a lot of the issues that are being reported, and I don't use the DTD code (in fact I'm about to look into adding a compile time option to turn it all off), so it's not a great fit.
If you fit the bill, and might be able to spare the time to help deal with it, please get in touch (here or directly). -- Scott