Stephen Chao - 2008-07-14

Executing more instructions then jumping is correct behaviour (called delay slots).  Check out:
http://www.zophar.net/documents/psx/psx-documentation-project.html
It has all the details on the CPU opcodes (and everything else to do with the PSX hardware).

I'll take a look at this bug, but I'm not sure how far I'll get...