psql overwrites command line

I am working my way through the tutorial in the official docs. I am on
Ubuntu 14.04 (Unity).

Twice I have had a series of tildes, one per line, show up after a command
is executed, followed by END. The cursor is blinking at END, but there is
no command prompt. I did \q and then the command prompt re-appeared, but
the command before it, and the result, vanished.

Now I am also getting a situation where the cursor does not go to a newline
while writing out commands, and instead starts overwriting the existing
command from the beginning:

--
her.datSELECT weather.city, weather.temp_lo, weather.temp_hi, weather.prcp,
weat
--

Then I am also getting scattered pieces of the commands within the results,
like this:

--
mydb=# SELECT * FROM weather, cities WHERE city = name;
WHERE city =name;
city | temp_lo | temp_hi | prcp | date | location
---------------+---------+---------+------+------------+-----------
San Francisco | 46 | 50 | 0.25 | 1994-11-27 | (-194,53)
San Francisco | 43 | 57 | 0 | 1994-11-29 | (-194,53)
(2 rows)

;
city | temp_lo | temp_hi | prcp | date | location
weather.city;
---------------+---------+---------+------+------------+-----------
San Francisco | 46 | 50 | 0.25 | 1994-11-27 | (-194,53)
San Francisco | 43 | 57 | 0 | 1994-11-29 | (-194,53)
(2 rows)
--

Note the extraneous semi colon above the location in the second table, as
well as the extraneous weather.city; and the duplicated WHERE city =name;
in the first table.

Can someone tell me a) what is going on here and b) how to fix it? Thanks.