HD Partition not mounting

I have a problem with my external hard drive, one of the partitions is not mounting. I can see it using Disk Utility, i verified it and repaired it with no effect (in any case there was no report of problems for the disk). At this point i have no idea what is wrong with it, and i need to get some files from there. Any help would be appreciated. Thanks!

(I'm using Leopard)

Anyone? any help? please?

Which external hard drive and Mac are you using? It maybe a known problem.
However, I would recommend getting Alsoft's Disk Warrior .
It is an excellent tool that may allow you to fix your hard drive with no problems. It also could help in recovering files.
But I would prepair to possibly reformat the external HD...

I think the problem is due to my HD's box, the HD is good but the box is a cheap one (I/O Magic), it goes to sleep sometimes while the partitions are mounted and, as you know, OSX doesn't like that.
I was hopping to avoid buying software, but at this point it seems to be the only option, i tried a demo for Data Rescue II and it can see the partition and all the files in there.