mpeg2enc - Sample rate is greater than permitted

[root@vdr .vdr-burn.PlkO6M]# png2yuv -n1 -f25 -It -L1 -v0 -j /etc/vdr/plugins/burn/simpsons-1.png | mpeg2enc -q 2 -a 2 -n p -f 8 -v 2 -o abc.wmv
   INFO: [mpeg2enc] SETTING EXTENDED MMX for MOTION!
   INFO: [mpeg2enc] SETTING MMX for TRANSFORM!
   INFO: [mpeg2enc] SETTING EXTENDED MMX for PREDICTION!
   INFO: [mpeg2enc] Selecting DVD output profile
   INFO: [mpeg2enc] Interlaced input - selecting interlaced encoding.
   INFO: [mpeg2enc] Encoding MPEG-2 video to abc.wmv
   INFO: [mpeg2enc] Horizontal size: 720 pel
   INFO: [mpeg2enc] Vertical size: 576 pel
   INFO: [mpeg2enc] Aspect ratio code: 2 = 4:3 display
   INFO: [mpeg2enc] Frame rate code:   3 = 25.0 (PAL/SECAM VIDEO / converted FILM)
   INFO: [mpeg2enc] Bitrate: 7500 KBit/s
   INFO: [mpeg2enc] Quality factor: 2 (Quantisation = 2) (1=best, 31=worst)
   INFO: [mpeg2enc] Field order for input: top-field-first
   INFO: [mpeg2enc] Sequence unlimited length
   INFO: [mpeg2enc] Search radius: 16
   INFO: [mpeg2enc] DualPrime: no
   INFO: [mpeg2enc] Using one-pass rate controller
   INFO: [mpeg2enc] GOP SIZE RANGE 9 TO 15
   INFO: [mpeg2enc] Setting colour/gamma parameters to "PAL B/G"
   INFO: [mpeg2enc] Progressive format frames = 0
**ERROR: [mpeg2enc] Sample rate is greater than permitted in specified Level
[root@vdr .vdr-burn.PlkO6M]#