Portable App check for new applications issue.

All,

I have been using Portable Apps (PA) for many years now and found an interesting difference between using it @ work and on my home networks.

Let me set up with the environments:
1) Work is behind FWs and content filters that are beyond my control (I have tried this at SEVERAL different work places so it seems a common issue).
2) Home is an open network behind a firewall that I control.
3) All PA applications are installed @ all times.
4) Updates are attempted through the PA Update facilities.
5) Additional PA configured Apps are installed (About 10 that I personally tested & built).
6) Get new Apps is run.

Here are the differences:
@ Home... All works as expected and individual NEW applications that require install are listed.
@Work... (I presume that a firewall/content filter intercepts the request), ALL applications installed or not are listed with installed applications GRAYED OUT.

Any thoughts? What site is being accessed that may be blocked? Is there a way to prevent this without attempting to access a commonly blocked URL/Website/IP?

Thank you,

Robin