No stats after a few hours

We are currently evaluating Netflow Analyzer 4 to make sure it will properly work in our environment. Although the problem we are seeing is that after about 2 hours there is no new netflow data being processed. It is still running and we are able to access the webpage but all the latest stats are at zero. I'm thinking now that it simply can't handle the load. We are exporting netflow data from 4 Cisco GSR's totaling about 450Mb traffic combined. The spec's for the hardware are below. I would assume that should be enough performance. Also I do keep seeing this error in netflowout0.txt which might explain why we see no new stats after a few hours.

[09:20:11:549]|[11-23-2005]|[com.adventnet.netflow]|[WARNING]|[14]|:%S CRITICAL: Reader exception, trying to abort collector module |

If this is not performance related any ideas would be causing this? Thank you.

Hardware/OS:
Slackware Linux - Kernel 2.6.11.8
AMD 64 3400+ CPU
1 GB RAM
250GB SATA Drive