AVR-Chat

hi! 
 I'm using sp12 and avrdude with a stk200 for writing fuse bits to a
ATTINY2313. I have 2 dead uCs. I tried to write lfuse = 0xe0 for using
external clock source and avrdude showed an error. After this I all
the fuses are set to 0xff. Of course I cannot program or write new
fuse bits anymore.Is there any way to fix this or I have to buy a new one?

here is the dump from sp12:
   11111111 are the fuse bits read from an ATtiny2313
   0xxxxxxx - CKDIV8 - divide clock by 8 (page 22)
   x0xxxxxx - CKOUT output clock on pin D2
   xxSUxxxx - start-up time (datasheet page 24)
   xxxxCKSE - CKSEL (datasheet page 22-24)

   11111111 are the high fuse bits read from an ATtiny2313
   0xxxxxxx - debugWire enabled
   x0xxxxxx - EEPROM preserved in chip erase
   xx0xxxxx - serial programming enabled
   xxx0xxxx - WDT always on (page 41)
   xxxxBODx - BODLEVEL (page 34)
   xxxxxxx1 - reset-pin enabled (page 52)

thanks in advance !