These packages fix up various problems found with
the selinux settings in Scientific Linux 4.2.

Problems include:
AFS does not start
GFS does not start
USB drives will not mount
CD-ROM and DVD's will not automount

To determine if it is selinux that is causing problems you 
should look in /var/log/messages and look for lines that have
avc in them.  Such as

audit(1134658441.480:3): avc:  denied  { mount } for  pid=17441 comm="mount" name="/" dev=dm-7 ino=26 scontext=user_u:system_r:initrc_t
 tcontext=system_u:object_r:unlabeled_t tclass=filesystem

These packages will be in Scientific Linux 4.3.  And if they pass 
all the tests, they will be put out as errata for 4.2.