I have been using two TowerRAID boxes connected to a Windows 7 pc by eSata. I can connect to these with my iMac over the network with no problems. However, I removed the small TowerRAID and replaced it with a Mediasonic hardware RAID 0 array connected by USB 3.0 cable. All computers on the network can see it, and other PC's can access it with no problem. However, my iMac can see it on the network, but won't mount it. I always get the "There was a problem connecting to the server..." message. I can still mount all other drives on the PC with no problem.

I'm not sure how to tackle this.
Which factor(s) might be at fault?
1) RAID 0 array (first time I have used RAID 0)?
2) Connected by USB 3 instead of eSata?
3) Mediasonic box (worked directly with iMac, but first time I tried to network to it)
4) Sharing settings (I've got it wide open with all access to "everyone")?
5) Other?

Any ideas greatly appreciated.