I was searching for answers on this forum for CD burning issues. I came across your post and you have the exact same issue I'm experiencing.
On my 18 track project using 48x Verbatim CD-R, the burning time increases to 500 minutes! Just climbs and climbs. One would think it's your burner wearing out. Well, I can burn CD's flawlessly using ImgBurn and Nero 8.
I have a ASUS DRW-24B1ST burner. CD Architect used to work like a charm years ago on my Windows 7 64-bit machine. I'm surprised I didn't find a LONG thread about CD Architect issues. Looks like people don't burn CD's anymore and that's why you don't hear about some issues with the software.
You mentioned you installed a new burner. Did the old burner work?