NOT reproducible with "AOO 4.0.1   – German UI / German locale  [Rev. 1524958 2013-09-20 11:40:29]" on  German WIN7 Home Premium (64bit)", “historic”  4.0  User Profile used for all  predecessor versions:

1. Download / open  Attachment 61566 [details] for Bug 101087, click before first word of
   text
2. <control+f> for 'Find'
   > Find and Replace dialog opens
2. Copy / Paste "adipiscing" from here to "Search for" input line
3. If necessary uncheck all search options
4. [Find] (several times) 
   > Will find "adipiscing"  in endnotes 1, 4, 

No bug?!?

Additional info:
(k) but there might be a problem. to reproduce it redo the test, but in step 1
    click behind last word of last endnote 12. 
    Result: "adipiscing" will not be found
(l) But a "Replace all" will find and replace both "adipiscing" doing (k)
    Strange!

@David Paenson:
Thank you for your feedback – unfortunately important information we will 
need to reproduce your problem is missing.
Please add all information requested in following:
a) Write a meaningful Summary describing exactly what the problem is
b) Attach a sample document (not only screenshot) or refer to an existing 
  sample document in an other Bug with a link; to attach a file to this 
  bug report, just click on "Add an attachment" right on this page.
  If you want to attach a test kit with multiple documents zip them into
  a single testkit.zip and attach the  testkit.zip
c) Contribute a document related step by step instruction containing every 
  key press and every mouse click how to reproduce your problem 
d) Attach screenshots with comments if you believe that that might explain the 
  problem better than a text comment. Best way is to insert your screenshots
  into a DRAW document and to add comments that explain what you want to show
e) if possible contribute an instruction how to create a sample document 
  from the scratch
f) add information 
  f1) what EXACTLY is unexpected
  f2) and WHY do you believe it's unexpected (cite Help or Documentation!)
  f4) concerning your Operating System (Version, Distribution, Language)
  f5) concerning your AOO version (with Build/revision ID if it's not a 
     public release) and localization (UI language, Locale setting)
  f9) Whether that worked in former OOO / AOO Versions

Really very very sorry. After closing and reopening this lengthy document with 400 endnotes i can now search the whole text including the endnotes. So no bug there after all.

@David Paenson 
Strange, I am pretty sure that you found a bug, but may be a tricky one, only visible under particular circumstances. Can you confirm my obsersvations (k) with that other sample document? And may be something similar in your document?