It sounds like Smart Identification might be the culprit and can impact performance for web tests.

You can change it in the File>>Settings>>Run menu and click the Disable Smart Identification during the Run session option.

If you don't want to change the settings, you would put this code in the beginning of each script you wanted to run.

Set App = CreateObject(''QuickTest.Application'')
App.Launch
App.Visible = True
App.Test.Settings.Run.DisableSmartIdentification = True

Another thing that might help speed things up is disabling the run arrow:

Set UFT's 'Run Mode' to Fast. To set in UFT, go to OptionsRun. This setting changes the script's run behavior so that it will run without the execution arrow to the left of the Expert view (or Keyword view).