COM errors

I am using a VB component for encryption/decryption of data. It in turn uses the CAPICOM EncryptedData object as provided by Microsoft. Having instatiated the object successfully, I am trying to run a method on that object which fails ~60% of the time for no apparent reason. The weird thing is that it this shouldn't happen, because there is an On Error Resume Next statement in the VB which then checks for errors in the CAPICOM decryption and acts accordingly. However, it seems that PHP is getting to the error first and throwing a wobbly.. is this a possibility? Any suggestions gratefully received! BTW, I totally new to PHP, as you can probably guess! Dirc