After I took a look here into the archives decided to ask about the following issue:
When I try to launch a WR test from TestDirector the addin initially selected (Web Test) is lost. What maybe the reason? I am using WR 7.6.
Long shot - but check this out on the individual test you are seeing the issue with.
When you record a test and save it out, and have launched WinRunner with an add=in selected at start-up, this information is stored in the test.
Verify in your test that the Web Addin is selected to load with the test by opening the test, ten go to Test Properties, cllick the add-ins tab and ensure Web-Test is checked.
If it isn't, it isn't going to load the add-in when TD launches the test remotely.
Insanity: doing the same thing over and over again and expecting different results