It could be any number of things, like a slow hard drive, a computer not able to record multitrack audio, or that's not optimized for audio??? You might be overdriving the inputs? Unfortunately you didn't notice the bright red warning at the top of the question field... the one that says we need ALL your system and software information. Capture 2 offers minimum system specs, that will work for smaller projects if you have only minimum specs, but as you get into LARGE track numbers the processor speed, RAM and hard drive all come into play.
Personally, I am using a Lenovo laptop, with a 2.3g quad core processor, 8 gigs of ram, and an SSD drive...I have a ai24, and I can run all inputs without a hitch, but if I try that on a computer with a FW400 port (I have 2 different PCI slot cards..1 = FW400, 1 = FW800) there are dropouts, and it quits recording.
I work with a number of HOW's and they are all struggling, and have equipment that isn't always capable of recording digital. However, we have provided a wealth of information in the 'Knowledge Base"
There you will find optimization tips for your computer, and LOADS of help with other related things, like Capture, Studio one, and your 32ai.
Make sure your computer doesn't go to sleep (ever) and energize ONLY the tracks you need (one button record) energizes all tracks and inputs and auxes... If you only have 2 gigs of ram or so you will NOT have much luck recording.