If you're adding a statement of type string and you're hitting the return key for saving too fast (before the save-button gets enabled) you're accidentally adding a "\n" to the string-value (I guess because the input box in fact is a textarea). When trying to save afterwards you're getting a "malformed input" error from the validator because of the "\n".
The same issue can probably occur for URLs.

Version: unspecified
Severity: major
Whiteboard: u=dev c=frontend p=5 s=2014-04-01