Weird nfs problem

[d1temp@telia.com]

On servar A I have the following in /etc/exports
-------------
/var/spool/mail B(ro,no_root_squash)
/home           *.domain.topdomain(rw)
-------------

and the following in /etc/fstab
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B:/proj/somethin/Web/html/extern-web /external_web nfs defaults 0 0
B:/proj                              /proj2        nfs defaults 0 0
-------------


On servar B I have the following in /etc/exports
-------------
/home *.domain.topdomain(rw)
/proj/something/Web/html/extern-web A.domain.topdomain(rw,no_root_squash)
-------------

and the following in /etc/fstab
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A:/var/spool/mail  /proj/var/backup/mail   nfs  defaults  0 0 
A:/home            /proj/var/backup/home   nfs  defaults  0 0
-------------

Server A can mount B:/proj/something/Web/html/extern-web but not
B:/proj (giving the following error message: "mount: B:/proj failed, 
reason given by server: Permission denied")

Server B can mount A:/var/spool/mail but not A:/home (same error as
above)

Tried various options in the export file, but no difference.

Any ideas at what this might be?

/Michael