It could also be a corrupted card causing the issue. I recently had a similar incident and trying a new card cleared it up. I actually had to use two different new cards as the first one I tried still did the same thing. The second card has worked fine.
HP-1 x 2, BCD396XT, BCD396T, BCD996T, PSR600, Pro2035, Pro2035+535, Pro2052, Pro94, Pro97,Pro-2096, R71-A, PCR-100 x 2, PCR1500 and 12 other scanners/recievers.