I have a somewhat similar setup, except I am using Jaws 7.0 and have 2 GB 
of memory.

Jaws shortcomings aside, having two copies of Word, one copy of Adobe 
Reader and Jaws open at the same time, and doing a good bit of 
cut-and-paste (filling up the clipboard) will be using a lot of memory, 
and 500 MB (I assume 512 MB) isn't a whole lot these days. It sounds like 
a somewhat older computer is in use. Is it feasible to switch to a machine 
with more memory?

You might try defragmenting the hard disk if that hasn't been done 
recently, along with the other good suggestions mentioned.

If you have Norton SystemWorks, try a one-button checkup, which can fix a 
number of common "errors", including int he registry.

By the way not everyone is aware of it, but you can unload and reload Jaws 
quickly without speech: Insert-F4 (with confirm) to uninstall Jaws, then 
Windows Key-R to open Run, type jaws8 and press enter, and Jaws will coem 
back in a few seconds. (replace "8" with whatever version of Jaws is in 
use, without any zeros at the right - e.g., jaws 7, jaws 81, jaws 9...) I 
believe this will work with any version of Jaws from 5.1 onward.

Rod