sendKeys inserts special characters in the fields

SendKeys function adds me an ASCII Null in the end of string or instead of commands like Enter, Arrow Down, Page Down(but TAB works correctly). I have this problem only in Firefox.
I could use setText for setting text, but I still need Arrow Down and Enter buttons…

There is my code:
WebUI.sendKeys(findTestObject(‘to’), Keys.chord(‘l’, ‘i’, ‘b’))
WebUI.sendKeys(findTestObject(‘to’), Keys.chord(Keys.ARROW_DOWN))
WebUI.sendKeys(findTestObject(‘to’), Keys.chord(Keys.ENTER))

Thanks in advance!

I have the exact same problem and I wonder if you have found a solution?
For my part I want to use Keys.TAB to change of text field. Actually, I want to trigger an error message with WebUI.sendKeys(myTestObject, "") but as it stays into the text field, the error does not appears…
In advance, thanks