The locking issue is more of a safety concern than anything...While your burning, if the drive isn't locked, any other program can access it at the same time ImgBurn is burning resulting in a bad burn/coaster. Its not a firmware issue.
You have "Verify" checked, it is highly recommend to verify each burn. What that does is, ImgBurn burns the files to a disc, after it completes it will eject the disc (mine ejects and then automatically closes again so that it can verify), when it verifies it looks just like it does burning but whats its doing is verifying the file integrity of the files on the disc, to the files on the hard drive.
If its burning slowly (2X is slow), its either the discs aren't rated higher than 2X (unlikely) or your DMA is off.
Please go here to rectify your problem - http://forum.imgburn.com/index.php?showtopic=59