Open up Spin It Again and click on Settings. In the Audio settings, make sure that the Sample Rate setting is set to 44100 and the Bit Depth setting is set to 16-bit. If that fixes the problem, see if there are any updated audio drivers for your sound card - if you want to record with different settings.
If that's not the problem, try this: on the recording tab, make sure that the recording folder is set to a local drive (not a network drive) and that you've got plenty of hard drive space on that drive.
If all else fails, submit an Acoustica Support Request and send us the spinagain-log.txt file, which is located here:
%appdata%\Acoustica\Spin It Again\spinagain-log.txt
Another way to find the log file is to click on the Windows Start menu, select All Programs, then Acoustica Spin It Again and finally "Logs."
If your copy of Spin It Again is older than verson 2.5, the log file would be here:
C:\Program Files\Acoustica Spin It Again\spinagain-log.txt
If you have Windows Vista, click the "Compatiblity Files" option in order to reveal the most recent log file.