I had similar problems recently while trying to install a single 80GB drive. My head is bunged up with Man Flu at the moment, nevertheless, I'll try and suggest something worthwhile for you to check....

Using Hyperterminal etc. get to a Bash prompt and run 'fdisk'. Type p<return> and copy/paste the output in here. You should see something like: Code:
Disk /dev/hdc: 16 heads, 63 sectors, 23392 cylinders
Units = cylinders of 1008 * 512 bytes

Device Boot Start End Blocks Id System
/dev/hdc1 1 66 33232+ 5 Extended
/dev/hdc2 67 132 33264 83 Linux
/dev/hdc3 133 165 16632 10 OPUS
/dev/hdc4 166 23392 11706408 83 Linux
/dev/hdc5 1 33 16569 83 Linux
/dev/hdc6 34 66 16600+ 82 Linux swap


... except that, and ISTR, yours should read "hda" instead of "hdc". The numbers will also be different but the overall partition structure should be the same.