what version of php does Zen Cart 1.2.6 need

I have a Zen cart store built on Zen cart 1.2.6
I know I have to upgrade, but not sure I can handle it my self
My hosting company is giving me a quote on upgrading it but I’m not to sure they can handle it ether.

My main problems right now is that the admin utility is very slow. It seems to take for ever to add product attributes. I feel part of the problem is the server that the hosting company has us on. They have a faster server but say they can not move us to it because the version of PHP is newer than PHP4
Here is there exact quote (Because your store is in Zen cart 1.26, which is built in PHP4, we cannot move the current website to that server.)
I have a test server that I have been using to test changes before I change the main site. I have had this at PHP 5.1.2 for over a year running Zen cart 1.2.6 and have not had any problems
So is my hosting company wrong, will Zen cart 1.2.6 run with a new version of php?

And if any one has suggestions for hosting, and help upgrading, please let me know.
I welcome all comments

Zen Cart 1.2.6 does run on php 5 however it is NOT supported,

so Technically your host is correct,

This is prolly off topic, but I just peeked at your site and according to the footer you have An Infinity eCommerce Solution.

That in itself is not a real problem, but the folks you are paying should be the one supporting it if they are going to claim the code.

Kim, I agree, but kind of stuck for now
how did you know what the hosting comp. was, as I did not list the site address?

A little simple detective work. You only have a few posts, I looked them up and found a URL. Looked at the site and clicked the link in your footer.