Exchange 2003 defrag hang

I kicked off a defrag on our 50gig last night and it ended up hanging at 56% for about an hour and a half. I checked the I/O Reads and Writes on eseutil process and it wasn’t updating. I hit ctrl-con the eseutil screen and the util immediately updated to 58%. Roughly 5 mins later the I/O reads and Writes stopped updating again, hit ctrl-c and up to 60%.
I’m currently watching it go through the rest of the process, and will hit ctrl-c at each lockup but does anyone know what would be causing this?

And yes, I created a backup of the database before running the defrag.