Bitrate & length modifying

Because my hard drive got jinxed, a lot of my MP3 files have incorrect bitrate and length info. Is there any way to change these? As an example, mp3tag show one file being 56Kbits & 1:06:21 in length, but WinAmp shows the file at 320Kbits and 1:26 length (correct numbers).

Use mp3val or Foobar's utilities to fix the headers of these files.
I doubt that this is due to some hdd problem as it would mean that specifically som bytes in the header got corrupted and the rest is still ok ... Anyway - try to repair the files with those tools.
Both tools are freeware at the time of this post and can be found with an internet search.