This is really weird.

New install on Monday.
Design and tweaking of Admin controls all throughout Tuesday and Wednesday.

Now today, Thursday, any changes I make to the files or within Admin are not being applied.

Examples:

1) Turned off display of weight and "this product was added" from individual product page.

2) In english.php file, changed text from "larger image" to "Enlarge Image". No change. So I went into the template and hard coded the change. No change.

3) Search side box. In english.php file, changed box heading text from "Search" to "Search AAGlockShop" ... no change.

I am not receiving any error messages anywhere (such as can not write to file, etc).

Add-ons installed:
a) Monthly Sales and Tax Summary Report
b) Column Layout/Grid Layout for Products Listing
c) Footer Menu
d) Image Handler 2 for v1.3.x

Everything worked fine after each of the above installs, which I did on Tuesday and Wednesday.

Any ideas of where to look for the problem of what could suddenly stop changes to files and Admin settings from being applied?