I am sorry to hear you are running into this problem.
Let's try several options:
1. Please add additional WaitForExists step for the element you are verifying or for some of the slowest element on the page.
2. Set Ajax to something different than 0 (e.g. 2000).
3. As a really last option you can add Execution Delay to pause the test for a set amount of time.
If the issue persists please:
1. Send us the execution log.
2. Please record a Jing video demonstrating the entire process, so we can better understand what is happening.
3. Please provide us with a copy of your test and if it is possible grant us access to your application so we can reproduce the issue on our end and give you a solution. If it is not possible to grant us access to your application, please take a Fiddler trace and attach it to a support ticket in a zip file. You can capture a Fiddler trace using FiddlerCap.
Hope to hear from you soon.