SRV server will only sometimes display output from my scripts the first time I run it. Even using a simple test it doesn't usually display any output:

<?php
echo 'this is a test.';
?>

It usually hangs with a status message at the bottom:

"Waiting for http://localhost:8080/file:/C:/allegro/temp/test.php?DBGSESSID=-1&PHPEdHidden=54902"

This status message will not go away and SRV will not work again without restarting PHPEd (shutting down the webserver and running again will not fix it). Sometimes it will work the very first time I try to run it after starting PHPEd, sometimes it won't work at all. I'm not getting any error messages, and it does work about 10%-20% of the time.

I'm not even trying to run debugger or profiler right now.

PHPEd 4.6.2 build 4629
PHP 4.4.4

I just saw there was a Build 4631 which is I guess newer. I installed that, but it doesn't fix this issue.

I think SRV works fine.
What Antivirus software do you use?
We have many reports similar to yours and all finished up with bitKeeper software which affects any web server, not only SRV and therefore needs to be UNINSTALLED compltely. Then everything works like a cham.

Antivirus is Symantec Corporate. No BitKeeper.

I had PHPEd v 4.0 installed with SRV working, and the same antivirus was running then. Only after the upgrade to 4.6 have the troubles started.

When SRV does work, there's no lag.

I have found that if I click the stop button to stop processing the page and try to run it again, I can usually get it to work after a couple of tries (usually around 4). Could it be a problem instead with the internal browser? PHPEd itself doesn't hang, and if I choose to shut down SRV, it shuts down immediately.

Norton Antivirus and Norton Internet Security are also snooping in the local IP traffic made by locally running Web and therefore it may affect functionality and cause all the lags. Although, I'd say that with NIS 2002 it works quite smoothly. Have no idea about NAV and about versions released after 2002.
You may want to try on a clean machine and make sure that SRV works with no hangs.