adding lyric to pickup-note in vocal line causes the note to disappear

I am trying to write one 4-4 bar plus one eighth-note pickup for voice and piano. I write this voice part first: I enter the notes and then go to add the lyrics. I select the pickup note, hit Control-L, and then right-click because I want to make the font size bigger (16). As soon as I do this the pickup eighth-note has changed to a vertical line in the staff (??). In attempting to undo this (Undo) the vertical line disappears, so now where there's supposed to be an eighth-beat there is just blank staff (but eighth-rests are still in both staves of the piano part at the pickup). That's annoying enough. But then I am unable to add anything to this; unable to add any kind of pickup. When I try to add a note there the note I write replaces the downbeat note of the next bar. I give up, start over, only to have the same thing happen. What is happening, and what should I do? (How can I change the lyric font size without this other weird stuff happening, and how do I add a pickup to this blank space? I even tried right-clicking the bar and going to measure properties, but it showed everything normal--nominal 4-4, 1-8 as the pickup bar, thus the program is providing for something to be there but nothing can be entered in). Please help!!
Thank you