Since upgrading to version 1.6, my build no longer gets tagged appropriately. I tested the tag command from a previously successful build, and that tag command still works.

Console output:
Started by user trandall
[TW_BA_IMP2_B2C_INST] $ "C:\Program Files\CVSNT\cvs.exe" -q -z3 update -PdC -D "Monday, May 2, 2011 3:54:45 PM UTC"
$ no changes detected
No emails were triggered.
[workspace] $ sh -xe C:\DOCUME~1\trandal\LOCALS~1\Temp\hudson8710292068814448345.sh
cygwin warning:
MS-DOS style path detected: C:\DOCUME~1\trandal\LOCALS~1\Temp\hudson8710292068814448345.sh
Preferred POSIX equivalent is: /cygdrive/c/DOCUME~1/trandal/LOCALS~1/Temp/hudson8710292068814448345.sh
CYGWIN environment variable option "nodosfilewarning" turns off this warning.
Consult the user's guide for more details about POSIX paths:
http://cygwin.com/cygwin-ug-net/using.html#using-pathnames
+ rm -rf build-TW_IMP2_B2C_BUILD.tar
+ tar cvf ./build-TW_IMP2_B2C_BUILD.tar TW_BA_IMP2_B2C_INST
TW_BA_IMP2_B2C_INST/
TW_BA_IMP2_B2C_INST/.project
TW_BA_IMP2_B2C_INST/CVS/
TW_BA_IMP2_B2C_INST/CVS/Entries
TW_BA_IMP2_B2C_INST/CVS/Entries.Extra
TW_BA_IMP2_B2C_INST/CVS/Entries.Extra.Old
TW_BA_IMP2_B2C_INST/CVS/Entries.Old
TW_BA_IMP2_B2C_INST/CVS/Repository
TW_BA_IMP2_B2C_INST/CVS/Root
TW_BA_IMP2_B2C_INST/CVS/Tag
TW_BA_IMP2_B2C_INST/dat/
TW_BA_IMP2_B2C_INST/dat/CVS/
TW_BA_IMP2_B2C_INST/dat/CVS/Entries
TW_BA_IMP2_B2C_INST/dat/CVS/Entries.Extra
TW_BA_IMP2_B2C_INST/dat/CVS/Entries.Extra.Old
TW_BA_IMP2_B2C_INST/dat/CVS/Entries.Old
TW_BA_IMP2_B2C_INST/dat/CVS/Repository
TW_BA_IMP2_B2C_INST/dat/CVS/Root
TW_BA_IMP2_B2C_INST/dat/CVS/Tag
TW_BA_IMP2_B2C_INST/dat/readme.txt
TW_BA_IMP2_B2C_INST/java/
TW_BA_IMP2_B2C_INST/java/CVS/
TW_BA_IMP2_B2C_INST/java/CVS/Entries
TW_BA_IMP2_B2C_INST/java/CVS/Entries.Extra
TW_BA_IMP2_B2C_INST/java/CVS/Entries.Extra.Old
TW_BA_IMP2_B2C_INST/java/CVS/Entries.Old
TW_BA_IMP2_B2C_INST/java/CVS/Repository
TW_BA_IMP2_B2C_INST/java/CVS/Root
TW_BA_IMP2_B2C_INST/java/CVS/Tag
TW_BA_IMP2_B2C_INST/java/mapfre/
TW_BA_IMP2_B2C_INST/java/mapfre/CVS/
TW_BA_IMP2_B2C_INST/java/mapfre/CVS/Entries
TW_BA_IMP2_B2C_INST/java/mapfre/CVS/Entries.Extra
TW_BA_IMP2_B2C_INST/java/mapfre/CVS/Entries.Extra.Old
TW_BA_IMP2_B2C_INST/java/mapfre/CVS/Entries.Old
TW_BA_IMP2_B2C_INST/java/mapfre/CVS/Repository
TW_BA_IMP2_B2C_INST/java/mapfre/CVS/Root
TW_BA_IMP2_B2C_INST/java/mapfre/CVS/Tag
TW_BA_IMP2_B2C_INST/java/mapfre/mma/
TW_BA_IMP2_B2C_INST/java/mapfre/mma/CVS/
TW_BA_IMP2_B2C_INST/java/mapfre/mma/CVS/Entries
TW_BA_IMP2_B2C_INST/java/mapfre/mma/CVS/Entries.Extra
TW_BA_IMP2_B2C_INST/java/mapfre/mma/CVS/Entries.Extra.Old
TW_BA_IMP2_B2C_INST/java/mapfre/mma/CVS/Entries.Old
TW_BA_IMP2_B2C_INST/java/mapfre/mma/CVS/Repository
TW_BA_IMP2_B2C_INST/java/mapfre/mma/CVS/Root
TW_BA_IMP2_B2C_INST/java/mapfre/mma/CVS/Tag
TW_BA_IMP2_B2C_INST/java/mapfre/mma/readme.txt
TW_BA_IMP2_B2C_INST/ora/
TW_BA_IMP2_B2C_INST/ora/CVS/
TW_BA_IMP2_B2C_INST/ora/CVS/Entries
TW_BA_IMP2_B2C_INST/ora/CVS/Entries.Extra
TW_BA_IMP2_B2C_INST/ora/CVS/Entries.Extra.Old
TW_BA_IMP2_B2C_INST/ora/CVS/Entries.Old
TW_BA_IMP2_B2C_INST/ora/CVS/Repository
TW_BA_IMP2_B2C_INST/ora/CVS/Root
TW_BA_IMP2_B2C_INST/ora/CVS/Tag
TW_BA_IMP2_B2C_INST/ora/pdc/
TW_BA_IMP2_B2C_INST/ora/pdc/CVS/
TW_BA_IMP2_B2C_INST/ora/pdc/CVS/Entries
TW_BA_IMP2_B2C_INST/ora/pdc/CVS/Entries.Extra
TW_BA_IMP2_B2C_INST/ora/pdc/CVS/Entries.Extra.Old
TW_BA_IMP2_B2C_INST/ora/pdc/CVS/Entries.Old
TW_BA_IMP2_B2C_INST/ora/pdc/CVS/Repository
TW_BA_IMP2_B2C_INST/ora/pdc/CVS/Root
TW_BA_IMP2_B2C_INST/ora/pdc/CVS/Tag
TW_BA_IMP2_B2C_INST/ora/pdc/readme.txt
TW_BA_IMP2_B2C_INST/ora/sf/
TW_BA_IMP2_B2C_INST/ora/sf/CVS/
TW_BA_IMP2_B2C_INST/ora/sf/CVS/Entries
TW_BA_IMP2_B2C_INST/ora/sf/CVS/Entries.Extra
TW_BA_IMP2_B2C_INST/ora/sf/CVS/Entries.Extra.Old
TW_BA_IMP2_B2C_INST/ora/sf/CVS/Entries.Old
TW_BA_IMP2_B2C_INST/ora/sf/CVS/Repository
TW_BA_IMP2_B2C_INST/ora/sf/CVS/Root
TW_BA_IMP2_B2C_INST/ora/sf/CVS/Tag
TW_BA_IMP2_B2C_INST/ora/sf/readme.txt
TW_BA_IMP2_B2C_INST/ora/sp/
TW_BA_IMP2_B2C_INST/ora/sp/CVS/
TW_BA_IMP2_B2C_INST/ora/sp/CVS/Entries
TW_BA_IMP2_B2C_INST/ora/sp/CVS/Entries.Extra
TW_BA_IMP2_B2C_INST/ora/sp/CVS/Entries.Extra.Old
TW_BA_IMP2_B2C_INST/ora/sp/CVS/Entries.Old
TW_BA_IMP2_B2C_INST/ora/sp/CVS/Repository
TW_BA_IMP2_B2C_INST/ora/sp/CVS/Root
TW_BA_IMP2_B2C_INST/ora/sp/CVS/Tag
TW_BA_IMP2_B2C_INST/ora/sp/readme.txt
TW_BA_IMP2_B2C_INST/ora/spp/
TW_BA_IMP2_B2C_INST/ora/spp/CVS/
TW_BA_IMP2_B2C_INST/ora/spp/CVS/Entries
TW_BA_IMP2_B2C_INST/ora/spp/CVS/Entries.Extra
TW_BA_IMP2_B2C_INST/ora/spp/CVS/Entries.Extra.Old
TW_BA_IMP2_B2C_INST/ora/spp/CVS/Entries.Old
TW_BA_IMP2_B2C_INST/ora/spp/CVS/Repository
TW_BA_IMP2_B2C_INST/ora/spp/CVS/Root
TW_BA_IMP2_B2C_INST/ora/spp/CVS/Tag
TW_BA_IMP2_B2C_INST/ora/spp/readme.txt
TW_BA_IMP2_B2C_INST/ora/sql/
TW_BA_IMP2_B2C_INST/ora/sql/CVS/
TW_BA_IMP2_B2C_INST/ora/sql/CVS/Entries
TW_BA_IMP2_B2C_INST/ora/sql/CVS/Entries.Extra
TW_BA_IMP2_B2C_INST/ora/sql/CVS/Entries.Extra.Old
TW_BA_IMP2_B2C_INST/ora/sql/CVS/Entries.Old
TW_BA_IMP2_B2C_INST/ora/sql/CVS/Repository
TW_BA_IMP2_B2C_INST/ora/sql/CVS/Root
TW_BA_IMP2_B2C_INST/ora/sql/CVS/Tag
TW_BA_IMP2_B2C_INST/ora/sql/readme.txt
Archiving artifacts
Recording fingerprints
Skipping CVS Tagging as build result was not successful.
No emails were triggered.
Finished: UNSTABLE