[OS X TeX] synching in TS 3.18

[Nitecki, Zbigniew H.]

I just downloaded TS 3.18 and am having some trouble synching (sometimes).
I checked the info on the website that indicates what should appear in TexShop Preferences.
The default button gave me what is expected in three of the windows, in the fourth is
simpdftex latex --maxpfb --extratexopts "-file-line-error -synctex=1"

Synching works fine on a file I am currently using, but when I went back to a larger, older project (ongoing) for which I have the pdf file and the "master" source file opened, but the individual source files for sections are not, I got no reaction (I expected to get a locked source file--I haven't learned how to turn off the automatic locking--but at least I would know whit the relevant source file for that section is called).

In the past I have not had a problem with accessing these source files via synching from the pdf even if they are not currently opened.

 I currently have TexLive 2011 (I planned to get 2012, but realized that 2013 will be available after the weekend, so decided to wait). I am running OS 10.7.5.

Any idea what I should do?

Zbigniew Nitecki
Department of Mathematics
Tufts University
Medford, MA 02155

telephones:
Office    (617)627-3843
Dept.    (617)627-3234
Dept. fax    (617)627-3966
http://www.tufts.edu/~znitecki/