With HEAD of June 27, when I set a dprintf before starting the execution of the inferior, I see 4 unexpected =breakpoint-modified events for each such dprintf, when starting the inferior.  These events seem identical and don't seem necessary.

Session showing the events:

> gdb.7.7 -i mi loopfirst
=thread-group-added,id="i1"
~"GNU gdb (GDB) 7.6.50.20130627-cvs\n"
(gdb) dprintf 8,"h"
&"dprintf 8,\"h\"\n"
~"Dprintf 1 at 0x400570: file loopfirst.cc, line 8.\n"
=breakpoint-created,bkpt={number="1",type="dprintf",disp="keep",enabled="y",addr="0x0000000000400570",func="main()",file="loopfirst.cc",fullname="/home/lmckhou/testing/loopfirst.cc",line="8",thread-groups=["i1"],times="0",script={"printf \\"h\\""},original-location="/home/lmckhou/testing/loopfirst.cc:8"}
^done
(gdb) r
&"r\n"
~"Starting program: /home/lmckhou/loopfirst \n"
=thread-group-started,id="i1",pid="6709"
=thread-created,id="1",group-id="i1"
^running
*running,thread-id="all"
(gdb) 
=library-loaded,id="/lib64/ld-linux-x86-64.so.2",target-name="/lib64/ld-linux-x86-64.so.2",host-name="/lib64/ld-linux-x86-64.so.2",symbols-loaded="0",thread-group="i1"
=breakpoint-modified,bkpt={number="1",type="dprintf",disp="keep",enabled="y",addr="0x0000000000400570",func="main()",file="loopfirst.cc",fullname="/home/lmckhou/testing/loopfirst.cc",line="8",thread-groups=["i1"],times="0",script={"printf \\"h\\""},original-location="/home/lmckhou/testing/loopfirst.cc:8"}
=breakpoint-modified,bkpt={number="1",type="dprintf",disp="keep",enabled="y",addr="0x0000000000400570",func="main()",file="loopfirst.cc",fullname="/home/lmckhou/testing/loopfirst.cc",line="8",thread-groups=["i1"],times="0",script={"printf \\"h\\""},original-location="/home/lmckhou/testing/loopfirst.cc:8"}
=breakpoint-modified,bkpt={number="1",type="dprintf",disp="keep",enabled="y",addr="0x0000000000400570",func="main()",file="loopfirst.cc",fullname="/home/lmckhou/testing/loopfirst.cc",line="8",thread-groups=["i1"],times="0",script={"printf \\"h\\""},original-location="/home/lmckhou/testing/loopfirst.cc:8"}
=library-loaded,id="/lib/x86_64-linux-gnu/libc.so.6",target-name="/lib/x86_64-linux-gnu/libc.so.6",host-name="/lib/x86_64-linux-gnu/libc.so.6",symbols-loaded="0",thread-group="i1"
=breakpoint-modified,bkpt={number="1",type="dprintf",disp="keep",enabled="y",addr="0x0000000000400570",func="main()",file="loopfirst.cc",fullname="/home/lmckhou/testing/loopfirst.cc",line="8",thread-groups=["i1"],times="0",script={"printf \\"h\\""},original-location="/home/lmckhou/testing/loopfirst.cc:8"}