Oracle Database Discussions

we have a partitioned table that is range partitioned by month. It has partitions starting from feb_2010 to feb_2011
we forgot to split the overflow partiton since february and now I was running the alter table commmand to split the partition at mar_2011 and it has been running for a really long time (30 hours)? This is oracle 10.2.0.3 on rhel4. This is a pretty powerful server with 4 dual core cpu's and 96 gb of ram and also a dedicated emc cx4-240 disk sub system with 60 drives dedicated to thiss database. We are also using asm for our datatfiles.
I started the alter table command to split the partition yesterday at noon time so this has been running for bout 30 hours?
There are about 5 to 7 millions rows in each of the monthly partitions and then there was 30million rows in the overflow partition. The column width is small with only 6 columns and avg row length of 101.
i have been watching the process run and it ran a sort output for over 24 hours and i cant figure out why it is taking this long for only the amunt of rows the table has in it. it is now running another sort and it is dragging as well.
Could my temp file be corrupted? Other processes seem to be running fine as this is a data warehouse system and all other jobs are completing ontime?
The system has been more than 50% idle most of the time while this process has been running.
i dont want to kill the session and caue further problems.
Any thoughts on why this process could be taking soo long?
Thanks.