using cron to do a tar and mail for backup

["Simon Lok" <scl_(_at_)_lok_(_dot_)_com>]

 Hi,
 
 I've made myself a /etc/daily.local with the following contents:
 
 #!/usr/local/bin/bash
 
 #
 # backup the cvstree offsite
 #
 BT='backup_(_at_)_blahblah-offsitebackup_(_dot_)_org';
 SB='cvs tree backup from blahblah server'
 GPGOPTS="-a -r $BT -q -z 9 --batch --homedir /root/.gnupg -e";
 cd /export && tar cf - cvs_home | gpg $GPGOPTS | mail -s "$SB" $BT
 
 Funny thing is, each night, I get two or three copies
 of the (nowadays it's almost always three) of the backup!
 Weird.  It started out working fine, but then after a 
 month, it started sending out two copies once in a while, 
 and now three.  
 
 Any ideas?  Thx in advance.
 
 --SL
 
 
 
 OpenBSD 3.1-stable (GENERIC) #0: Wed Jul 31 09:34:38 EDT 2002
     root_(_at_)_nj006:/usr/src/sys/arch/i386/compile/GENERIC
 cpu0: Intel Pentium 4 ("GenuineIntel" 686-class) 1.50 GHz
 cpu0: FPU,V86,DE,PSE,TSC,MSR,PAE,MCE,CX8,APIC,SYS,MTRR,PGE,MCA,CMOV,PAT,PSE36,MMX,FXSR,SIMD
 real mem  = 804630528 (785772K)
 avail mem = 740126720 (722780K)
 using 5689 buffers containing 40333312 bytes (39388K) of memory
 mainbus0 (root)
 bios0 at mainbus0: AT/286+(00) BIOS, date 10/08/01, BIOS32 rev. 0 @ 0xfda74
 apm0 at bios0: Power Management spec V1.2 (BIOS mgmt disabled)
 apm0: AC on, battery charge unknown
 pcibios0 at bios0: rev. 2.1 @ 0xf0000/0x10000
 pcibios0: PCI IRQ Routing Table rev. 1.0 @ 0xf2f30/208 (11 entries)
 pcibios0: PCI Interrupt Router at 000:31:0 ("Intel 82371FB PCI-ISA" rev 0x00)
 pcibios0: PCI bus #2 is the last bus
 bios0: ROM list: 0xc0000/0x8000 0xc8000/0x1000 0xc9000/0x1000 0xca800/0x1000
 pci0 at mainbus0 bus 0: configuration mode 1 (no bios)
 pchb0 at pci0 dev 0 function 0 "Intel 82850 Host" rev 0x02
 ppb0 at pci0 dev 1 function 0 "Intel 82850/82860 AGP" rev 0x02
 pci1 at ppb0 bus 1
 vga1 at pci1 dev 0 function 0 "ATI AIW Radeon" rev 0x00
 wsdisplay0 at vga1: console (80x25, vt100 emulation)
 wsdisplay0: screen 1-5 added (80x25, vt100 emulation)
 ppb1 at pci0 dev 30 function 0 "Intel 82801BA AGP" rev 0x02
 pci2 at ppb1 bus 2
 fxp0 at pci2 dev 8 function 0 "Intel 82562" rev 0x01: irq 11, address 00:03:47:68:9b:ca
 inphy0 at fxp0 phy 1: i82562EM 10/100 media interface, rev. 0
 twe0 at pci2 dev 10 function 0 "3ware Escalade IDE RAID" rev 0x12: irq 11
 twe0: Escalade V5.7
 scsibus0 at twe0: 16 targets
 sd0 at scsibus0 targ 0 lun 0: <3WARE, Host drive #00, > SCSI2 0/direct fixed
 sd0: 293231MB, 37381 cyl, 255 head, 63 sec, 512 bytes/sec, 600537600 sec total
 pcib0 at pci0 dev 31 function 0 "Intel 82801BA LPC" rev 0x02
 pciide0 at pci0 dev 31 function 1 "Intel 82801BA IDE" rev 0x02: DMA, channel 0 wired to compatibility, channel 1 wired to compatibility
 wd0 at pciide0 channel 0 drive 0: <IC35L020AVER07-0>
 wd0: 16-sector PIO, LBA, 19623MB, 16383 cyl, 16 head, 63 sec, 40188960 sectors
 wd0(pciide0:0:0): using PIO mode 4, Ultra-DMA mode 5
 pciide0: channel 1 ignored (disabled)
 uhci0 at pci0 dev 31 function 2 "Intel 82801BA USB" rev 0x02: irq 10
 usb0 at uhci0: USB revision 1.0
 uhub0 at usb0
 uhub0: vendor 0x0000 UHCI root hub, class 9/0, rev 1.00/1.00, addr 1
 uhub0: 2 ports with 2 removable, self powered
 "Intel 82801BA SMBus" rev 0x02 at pci0 dev 31 function 3 not configured
 uhci1 at pci0 dev 31 function 4 "Intel 82801BA USB2" rev 0x02: irq 15
 usb1 at uhci1: USB revision 1.0
 uhub1 at usb1
 uhub1: vendor 0x0000 UHCI root hub, class 9/0, rev 1.00/1.00, addr 1
 uhub1: 2 ports with 2 removable, self powered
 isa0 at pcib0
 isadma0 at isa0
 pckbc0 at isa0 port 0x60/5
 pckbd0 at pckbc0 (kbd slot)
 pckbc0: using irq 1 for kbd slot
 wskbd0 at pckbd0: console keyboard, using wsdisplay0
 pcppi0 at isa0 port 0x61
 midi0 at pcppi0: <PC speaker>
 sysbeep0 at pcppi0
 npx0 at isa0 port 0xf0/16: using exception 16
 pccom0 at isa0 port 0x3f8/8 irq 4: ns16550a, 16 byte fifo
 fdc0 at isa0 port 0x3f0/6 irq 6 drq 2
 fd0 at fdc0 drive 0: 1.44MB 80 cyl, 2 head, 18 sec
 biomask cc40 netmask cc40 ttymask cc42
 pctr: user-level cycle counter enabled
 dkcsum: sd0 matched BIOS disk 81
 dkcsum: wd0 matched BIOS disk 80
 root on wd0a
 rootdev=0x0 rrootdev=0x300 rawdev=0x302