Jeff,
We have several warehouse deployments and have addressed some of these issues in the past. If I were in your shoes, I would keep an eye on one of the devices in client monitor. You can watch for roaming events, reauths, etc. I would also guess these are 2.4 GHz b/g clients. Make sure your radios are tuned properly. If you have a high density deployment, you may have some co-channel interference on the 2.4 GHz spectrum. Your clients won't want to roam if the signal strength is still strong, even though it's connected to a much further AP (sticky client). Consider reducing max power limits on the 2.4 GHz radios. Last, be sure load balancing is turned off; not good for roaming clients.
Feel free to add more detail and I'll try to help further.
Best,
BJ
