Running out of memory

Hello,
I recently posted to the user list that we are running doxygen on a large project and it is running out of memory.  I might be able to contribute some work to get past this problem if it represents a bug, or some room for improvement.  So, I joined this list.
 
Does Doxygen normally use so much memory relative to the code it is parsing?  (3.5 MB of code -> 2+ GB of pagefile usage)
Or is this an unusual case?
 
If that is 'par for the course', then what options are there for preventing Doxygen from running out of memory?
 
Along this line, I started to think that perhaps Doxygen could start to use a robust database to manage the large amount of information it has to hold onto (eg MySQL). I know this is a non-trivial step, so I'm not talking about it casually.
 
This could also be a step towards wish-list item #31 (Only regenerate those files that have changed.)
 
Alternatively, Doxygen could query asset managers for source code changes directly. (eg CVS, VSS, etc.) I assume that most people with large projects use some kind of source control. Does anyone have experience in this area?
 
And I'm sure you've considered a 3rd alternative where Doxygen could build doc-object files like a regular compiler.  (I guess these would be like the tag files?)
 
Anyway, don't flame me for my pipedream-type post. ;-)  I'm just interested in where things are going, and where I might be able to help.
 
Cheers and thanks for all your work,
Jacob Foshee