Microsoft Word from 97 to 2003 (and some Mac Word versions) — 10 characters

No repetitions, but doesn't quite match specs - 10 characters:

=rand(2,1) 

Output:

The quick brown fox jumps over the lazy dog. The quick brown fox jumps over the lazy dog. 

Matches specs, other than capitalization and punctuation, one repetition - 10 characters:

=rand(1,1) 

Output:

The quick brown fox jumps over the lazy dog. 

Newer versions of Microsoft Word use =rand.old(1,1) which duplicates d and 1.

There might be a way to use a field {=SUM(3,-2)} as input to rand() but my installation is having issues with fields -- namely, they're not working...

"Bob" has confirmed that {=SUM(3,-2)} (with some difficulty) can be used to replace the first 1, but = is repeated...

=rand({=SUM(3,-2)},1) 

Provided you get Word to update SUM first, the output is:

The quick brown fox jumps over the lazy dog. 

Sclipting — 36 characters

덆둥긇굵늖꽫긆깲닷덮긂롦닲롸껂걪덖륰댲걯덦넬댢건늆넠닆굺뎒걤닶댬首坼 

(expects empty input)

Explanation:

Push the string "the quick brown ,fo,x, jumps ove,r the lazy dog," 덆둥긇굵늖꽫긆깲닷덮긂롦닲롸껂걪덖륰댲걯덦넬댢건늆넠닆굺뎒걤닶댬 Retrieve last character from the string (",") 首 Regular expression string-split 坼 

The result is the list ["the quick brown ", "fo", "x", " jumps ove", "r the lazy dog", ""], which is automatically concatenated into a single string for output.

Perl 6 (76 chars, no doubles)

The script (will be mangled by the board software, but there's En Space up to Thin Space and NL and LF and tab)

say　EVAL lc q{<the Quiţk Brown fïX jUmpS ůvťɲ Tɨå ìšzY dOg>~&(127.CHR x 43)} 

• It uses EVAL (thanks again for making it uppercase) and <foo bar> quote words which supports all the special space characters as word separators.
• say joins the list of strings using space, works nicely here :)
• Next I use ~& and 127 to bit shuffle to plain ascii. Extra complication: 'Ŭ'.lc becomes 'ŭ' so that becomes an s instead of the r I needed. Adding 128 some extra times helps :)

A version with backslash escapes instead of unicode characters to show they're all different

say\x[3000]EVAL\x[9]lc q{<the\x[2003]Qui\x[163]k\x[2004]Brown\x[2005]f\x[EF]X\x[2006]jUmpS\x[2007]\x[16F]v\x[165]\x[272]\x[2008]T\x[268]\x[E5]\x[2009]\x[EC]\x[161]zY\x[200A]dOg>~&(127.CHR\x[0A]x\x[0D]43)} 

If you want to verify they're all unique, use this script (I used Qb"string" to have basic quoting with only backslash escapes)

.say for Qb"say\x[3000]EVAL\x[9]lc q{<the\x[2003]Qui\x[163]k\x[2004]Brown\x[2005]f\x[EF]X\x[2006]jUmpS\x[2007]\x[16F]v\x[165]\x[272]\x[2008]T\x[268]\x[E5]\x[2009]\x[EC]\x[161]zY\x[200A]dOg>~&(127.CHR\x[0A]x\x[0D]43)}" .comb.Bag.grep(*.value > 1).map: {.key.ord.base(16) ~ " $_" } 

Or execute it directly using

EVAL Qb"say\x[3000]EVAL\x[9]lc q{<the\x[2003]Qui\x[163]k\x[2004]Brown\x[2005]f\x[EF]X\x[2006]jUmpS\x[2007]\x[16F]v\x[165]\x[272]\x[2008]T\x[268]\x[E5]\x[2009]\x[EC]\x[161]zY\x[200A]dOg>~&(127.CHR\x[0A]x\x[0D]43)}" 

PHP - 67 bytes

<?echo$g^¶¥€¼½ˆ•.${~˜}=ÂÍåœÌýü¡¦Åþ¾’‹Ï†£‘ƲáºëÓâæݗߙ󖎸·³ø‰ï®ÜØÔ; 

Copy-Paste, save as Latin-1 (Ansi).

This is a 7-byte xor-cipher, using the string ¶¥€¼½ˆ• for salt.

One repeated character: $.

Haskell, 71 characters

map(\c->chr$mod(ord c)128)"tŨeఠquiţkĠbŲɯwnȠfѯxРjѵŭŰsܠůvťѲठѴѨѥਠlšzyଠɤկg" 

Yet another 7-bit modulo solution.

Repeated characters:

c 3 d 2 m 2 o 2 r 2 ( 2 ) 2 " 2 

First time golfing with Haskell; anyone more experienced in the language, feel free to improve. I wanted to make the anonymous function point-free to avoid having to mention a variable twice, but I don't know if it'd be a net benefit.