Left side boxes pop up in center

Hello This is my first post. I'm new to Zen cart and only have limited programming ability in VB and Autolisp, no html or php experience.

Zen Cart v1.3.9h
Running locally on xampp Apache v 1.7.3
Windows XP, 2-core, 4 gb memory, 4 tb storage, Nvidia G-force graphics card. 21", 1920 x 1280 WS display. 2-monitors.

Several add-on mods have been installed including NPF Templates with additional fields, media manager, easy populate, back-up 1.06 and Better Categories mod?

IE 6 & Fire-fox (latest version)

I'm building the website to the extent possible with a local server connection with Xampp services. I have modified my template extensively using Dream Weaver CS3. I have about 14,000 products in 42 categories uploaded successfully. I have only added a few images for test purposes so far. My total file size is about 53 megabytes.

Here is my question: am I running out of memory? Windows shows about 50-60% usage with Dream Weaver, Outlook ad 5 or 6 other windows open at any one time.

When I type http://localhost/zencart/index.php my home page appears after about 4-5 seconds. All of the text content from the left side-boxes including categories, manufacturer list, an a few other side boxes momentarily appear centered on the center of the screen and then jump into position.

I can't tell if I'm over taxing my system or if there is an error in a modification. The template itself all seems fine. The problem did not occur until I loaded several mods to test them. If it looked like something was not right, I deleted the existing files and entirely replaced with backup files and a matching MySQL database import file.

I'm not ready to go live for about two weeks so I can't install this on a remote server.

Does this sound like a problem with my Zen Cart file or just the nature of running the program locally?

I should note that Back-up 1.06 was working but now it hangs. I don't get a blank screen and it is running but it does not complete the file back-ups only the database export file.

The column jump is a feature of the /template_default/ stylesheet, and possibly other templates' stylesheets.
#navColumnOne and #navColumnTwo are styled with margin: auto; which centers the element in the available width. For an instant, the left column is the only thing in the main page area, so it starts in the center, then shifts over as the rest of the page loads. In a fast system, this may happen so quickly you don't see it.

Sigp220:

I'm not ready to go live for about two weeks so I can't install this on a remote server.
First thing I'd do is install it on a remote server. You can put the site down for maintenance and still work on it.

I've seen that behavior on remotely-hosted sites, and always assumed it was a slow server, but the only way you'll know is to put it up and see.