strange phenomenon

Hi.
I having a strange phenomenon- I have a part 720x50 size.
one time I changed the size from 720x50 to 735x50 and save it.
after a while I changed it back to 720x50 and again save it.
this part is a part from assembly.
now every time I open the assembly and/or the part I see doublesizes:
the 720x50 and the 735x50.
the moment I open the extrude sketch, only the 720x50 appears.
but when i close the program and open it again wuth this part thephenomenon happens again.
Please advice.
thanks.
OrenSolidworksAssemblies