So we are talking about VBA rather than VB ... OK, this is probably caused - would you believe - by Internet Explorer
security.
Basically the RTB is not trusted as safe by IE (the control itself is erroneously marked as safe but IE is configured not to believe it). Later service packs of Forms2 (also known as the
Microsoft Office Forms Library, i.e VBA's userforms) check with IE on whether they are allowed load and run a control. The policy for the RTB is to NOT load or run it, because the
'killbit' is set in the registry. This killbit setting is not accessible through the IE interface, so there are two primary workarounds
1) Use genuine VB6 to wrap the RTB in a usercontrol which you can mark as safe
2) Edit the relevant killbit setting in the registry (normal warnings about modifying the registry apply):
HKEY_LOCAL_MACHINE\Software\Microsoft\Internet Explorer\ActiveX Compatibility\{3B7C8860-D78F-101B-B9B5-04021C009402}
and change the 'Compatibility Flags' value from 0x400 to 0