Attempted to read or write protected memory in SAP 8.81 PL5

Hi

I seem to be suddenly getting lots of 'attempted to read or write protected memory' in an application I am writing using the B1DE

It seems to fail either when connecting to SAP or when initialising a recordset command

I have tried the usual tricks -

delete SM_OBS_DLL folder

reinstall client

reinstall DI API

I am on SAP 8.81 PL5

It's causing me real problems as I can hardly run my vb.net application

Can anyone help please ?

Many Thanks

Regards Andy