Britain's No 1, Greg Rusedski, has dropped one place to No 9 in the latest world rankings, but Tim Henman, the No 2, climbed one place to 17th despite three successive first-round defeats.
Rusedski's ranking is his lowest since he first moved into the top 10 in October after winning the Swiss Indoor Championship, but his drop came because he did not play last week.
Henman, by contrast, has been in poor form but had no points to defend last week. He moved up a place because Thomas Muster dropped from 16th to 21st.
Britain will play Ukraine in Group One of the Euro-African Zone of the Davis Cup for the second successive year when the two countries meet in Newcastle in April.
Ukraine beat Denmark 3-2 in Kiev over the weekend to qualify for this second-round tie, which Britain must win to progress to the World Group Qualifying round in September.
Former world No 1 Steffi Graf celebrated her comeback eight months after a knee operation with a straight-sets win in the first round of the WTA doubles tournament in Hanover.
Graf and her partner, Barbara Rittner, beat their compatriots, Meike Babel and Wiltrud Probst, 6-3 6-1.