Android constantly re-downloads inbox?

Guys,

I'm testing Zextras to see if it's worth purchasing. I installed it with this Zimbra edition:

Release 8.0.4.GA.5737.UBUNTU12.64 UBUNTU12_64 FOSS edition

However, after adding it on Android as a Corporate account, it seems to continue to re-download the inbox everytime I try to sync. I've also tried it with VMWare Horizon native android zimbra client, and while it seems to do a little better it often exhibits the same issue. Is this a known problem? Any suggestions how to fix? I *really* want Zextras to work and am very willing to pay if it does.

Thanks!