WinRAR problem

Ok, heres my situation, i got a CDI image of PSO, rar'd into one file (hlg_pso.rar) whose size is 503,147 KB. however when i open it up it displays the follwoing info:

hlg_pso.cdi
size 791,447,117
packed 19,765,517
ratio 2%

now the packed size is obviosuly wrong, since the file size is 503,147KB. I may have opened the archive when i had some old hlg_pso.rxx files in the same folder, could that have messed it up? anyway, when i try to open it, i get corrupted archieve errors. I konw the archieve works, because 2 other people have used the same one and it worked fine.

any ideas?? please?? i've tried everything i can think of.

-Buff