Just as a followup, what I did to over come this issue was to replace all the <BR> with **** in HomeSeer before the info was sent back to ML. When recieved in ML I replaced the all the **** back to <BR> So they could be used in a MultiLine Button.
I had a routine in ML before but would take upto 40 seconds to complete and no other processing could take place unil it completed. The same routine (VBScript) in Homerseer would complete in under 5 seconds and since it was done on another machine had no effect on MLServer.
I have found the MLStrings plugin is very useful but not as fast running a VBScript externally.