how to stop annoying screen jumps?

[John]

Hello:
I use Lyx 1.6.5 and Ubuntu 10.04. Lyx works fine, but if I am editing, 
then click the pdf icon to view the pdf output, then click back on the 
Lyx text to make a change, all too often the screen wildly jumps to some 
other part of the document.  For example, I might be editing the end of 
the document, and after returning to Lyx and clicking on a sentence the 
screen will jump to the first page, or somewhere else.  It seems to 
happen about 25% of the time.  Its very annoying, as I have to scroll 
around to re-find the sentence I want to edit.  Sometimes the screen 
even jumps again when I try to put the cursor on my desired sentence.  I 
don't know if it is related to having floating picture frames on some of 
my pages.  Maybe the problem would not occur if I had only plain text.  
Has anyone else had this problem?  Is there a fix? My document is about 
60 pages long.
Thanks, John.