Perhaps a stupid question...
Have you tried google to find a newer BIOS on other than the Gateway support site?
If you cannot find a newer edition of your BIOS, and it seems to hang, but can find the present edition, you could download a new copy and reinstall the present BIOS. Is this your current BIOS?
http://notebook.driversdown.com/note.../s_980_1.shtml
I found this post that seems to divide the problem into two parts, 48-bit LBA support and not recognizing more that 137GB.
http://www.wimsbios.com/phpBB2/topic8931.html
You might try to look at the setting and on the first page of the BIOS after the menu page, where the HDD is detected or its parameters can be set. Look to see if there is anything that can be opened or expanded to give you more options, one of which might be LBA. I too had a machine with a 137GB limit, but I found it would support LBA when I finally found my way to it. A machine that is no older than four to five years could be expected to have 48-bit LBA support.
If you can achieve LBA, the second demand seems to be that linux be installed within the first 137GB. You have tried putting boot and home there, but I might try to set up linux with three partitions (swap,/,/home) all within the 137GB limit, booting the system, then using its linux partitioner to expand the /home partition beyond 137GB, hoping that you both get boot and more than 137GB.