Another possibility: You've given us the code for doing the actual checkpoint... however, what is going on immediately preceding that? The reason I ask is that the component whose property you're checking (Aliases.TransactConsole.FormTransactConsole.PageControlTransact.TabSheetJobManager.omFormJobManager.JMPageControl.TabSheetJobs.cxJobManagerGrid.TomGridSite.TcxMaskEdit3.TcxCustomInnerTextEdit) MIGHT not actually exist at the time you're doing the checkpoint. In other words, if the object doesn't exist, the property doesn't exist... and you can't do a checkpoint against it.
Now, understandably, you can do an object spy and see the property and the object, however, in the course of running the tests, keep in mind that automation runs CONSIDERABLY faster so, when you perform an action, there may be a delay before the next step can actually be executed.
What I would do is try adding a check before your checkpoint call to WaitAliasChild on the text box. Wait for it to be present before you attempt the checkpoint. Once it comes back and is ready to be accessed, then do your check point.