Hi,

Our Exchange and Blackberry servers seem to have slightly different versions of CDO.DLL.
Is this likely to cause any problems?

Exchange: 6.5.7234.20
Blackberry: 6.5.7638.2

You should be fine, as long as the BES version is same or HIGHER than the Exchange version. In a perfect world, you'd want them to be the same... but sometimes that's just not possible.