In Fireworks CS3, was to make a frame on a text and had an option that when you add two letters, the track that sumia union, thus the effect on Picture1.
In Fireworks CS4, even enabling the option, the effect does not occur, see Picture2.
You can then say that this is a bug.
Recalling that use the version 10.0.3.011
I look forward to launching a fix the problem.
If you convert the text tgo paths before you add the stroke or Glow, do not ungroup it. If you ungroup it, choose Modify > Combine Paths > Join before adding the stroke or Glow effect. This is not something new to CS4, rather it has always worked that way.
The range kerning between two letters have been changed to the Tracking option in the Property Inspector.
You can also read up on all the Text Engine changes that occurred between CS3 > CS4, here, http://www.adobe.com/devnet/fireworks/articles/adobe_text_engine.html