I upgraded to 0.2.4 yesterday and it worked fine. Today I rebooted the N900 and started Flopswap and it did not perform a check. The checkbox in the settings is on. I shut down Flopswap, started it again, it didn't check so I pressed the Check button. It seems to be checking on start fine now.
For me it looks like that: the UI is constantly switching between the layouts but after some time the UI stabilized