I have crossed platforms with DS before so I know this can be done. Here some things to try:
1. If you move the DSS to a Win 98 machine do have the same problem?
2. For testing purposes, try using DS Write on 1 Win 2000 machine and use DS Read on 1 Win 98 machine.
3. Be sure to use a delay between consecutive DS Writes and DS Reads. The more the merrier.
4. Try predefining your data items in the DSS Manager.
5. Try sending scalar data as opposed to arrays or clusters.