I'm not sure this is a UBB problem (that's the software FT uses) or a browser problem. In any case, it wraps anything (not just URLs) after 127 or 128 characters. It does so by forcing a line break. Therefore, when you try to go to the long URL, your browser just picks up its first 127 characters and goes there. If you're lucky, you may get somewhere within the target site, though not to the page you wanted; if not, you'll get a "page not found" message."

While Dan's looking for the fix, you can copy each segment of the URL and paste it, segment by segment, into the location field of a new browser window. That's not an ideal solution, but even a 500-character URL will only be in four pieces, so it's not all that burdensome.