The file /etc/localtime appears to be corrupt when the UK/London is chosen as a
timezone as without it cvs diff works, with it the following is reported:

cvs diff
cvs diff: Diffing .
Index: JamaicaBibliography.bib
cvs diff: internal error: bad date 5 Jul 2005 22:35:30 -0000
===================================================================
RCS file: /home/simgroup/cvsroot/Documents/LightDocuments/JamaicaBibliography.bib,v
retrieving revision 1.25
*** glibc detected *** malloc(): memory corruption: 0x080de528 ***
cvs [diff aborted]: received abort signal

strace shows:

stat64("JamaicaBibliography.bib", {st_mode=S_IFREG|0644, st_size=123682, ...}) = 0
clock_gettime(CLOCK_REALTIME, {1123605286, 754151000}) = 0
stat64("/etc/localtime", {st_mode=S_IFREG|0644, st_size=1323, ...}) = 0
write(2, "cvs", 3cvs)                      = 3
write(2, " ", 1 )                        = 1
write(2, "diff", 4diff)                     = 4
write(2, ": ", 2: )                       = 2
write(2, "internal error: bad date ", 25internal error: bad date ) = 25
write(2, "5 Jul 2005 22:35:30 -0000", 255 Jul 2005 22:35:30 -0000) = 25
write(2, "\n", 1
)                       = 1