Hello and welcome to Apple Discussions.|
Reading your post, it sounds like you have done the correct printer queue setup. But since the 3380 is printing mostly blank sheets with the Canon PPD or Generic PostScript selected, this would be an indication that the printer does not have the PostScript license installed.
So, one suggestion would be to use an alternate driver, such as the UFR2. Most iR copiers support the UFR2 language as standard, while PCL and PS can be options.
You can download the UK English version of the latest UFR2 driver that will support your iRC3380 via this link.
The UK English driver can be used in the US region (I wasn't sure where you are located). The LTR and LGL sizes are still supported. I think the primary difference is the naming of the Canon devices.
Anyway, with this driver installed, you can add the printer queue again, just the same as you have done previously, but this time in the Print Using menu you need to select "Canon iR C Series UFR II (UK)".
See if this works for you and reply if needed.
MacBook Pro 17 Mac OS X (10.6.2) MacPro 2x3GHz Quad-Core, Xserve G5, iPhone 3G