When signs don't match it is a challenge to continue the relationship. Famous examples of not matching signs are Pattie Boyd and Eric Clapton. This famous couple divorced. Four years ago Pattie Boyd wrote a book about the marriage. It seems to have been her 'revenge' on Eric Clapton (see the news of 2006).
Pattie Boyd is born 17th March 1944 (time unknown) and she divorced Eric Clapton (30 March 1945, 20h55 in Ripley Surray, UK). They did not match much. Here is the (DD-rated so time is not official!) natal chart of Eric Clapton by Astrodatabank with the transits of the day of birth of Pattie Boyd.
He is an Aries, she is a Pisces (-); they are fundamentely different.
He is a Moon Scorpio, she is Moon Sagittarius (-) and that doesn't make it easy to get used to living together.
He is Mercury in Aries, she in Pisces (-); that is causing differences of opinion and interests.
Venus sextile Venus (+) so they liked each other...
Mars in Pisces for him, in Gemini for her (-) for fire first and fighting later. There are many of such examples on this blog.
Her Sun is biquintile his Moon (+) for a creative way to became a couple.
His Venus inconjunct her Neptunus (-) for lost illusions.
His Mars square her Uranus and inconjunct her Neptunus (--) and that is no good...
His Jupiter square her Saturn (-) is for ups and downs.
His Neptune parallel her Sun (+) for romance.
That is a lot of not matching planets and lights...