I came across this error recently. I keep below the 50 task sync limit by only sending up a maximum of 45 tasks at one time. However, it seems that certain larger tasks have caused the request to exceed the maximum limit allowed by the toodledo server.
Could I get the number for this limit? So I can do two tests before sending up the data. One to make sure there are less than 50 tasks sent up, and the other to make sure the size of the request is less than the maximum for the toodledo server.