Trouble searching for conditional text

[Jennifer Randel]

Hi everyone.
I'm having trouble searching for conditional text in Frame 6.0p405, on a
PC. 

Here's what's happening: I can search a book for one condition (for
instance, "comment") and the conditional text is found. However, when I
try to search for more than one condition at a time (say, "comment" and
"site users"), none of the comments (which I know DO exist) are found. 

Has anyone else had this problem? Any advice? 

Thanks in advance, 
Jennifer Randel