MSComm Control And Variant

I am using the MSComm control in an application that apparently has a memory leak. My data that supports this contention is derived from TaskManager. When my application is run TaskManager indicates the memory used by the system increases but not by my application. I have used Purify on the application and used CMemoryState on the suspect code all to no resolution. The MSComm control exposes a GetInput function that returns a VARIANT. After calling GetInput I then call VariantClear(&vret) on the the returned VARIANT. Is this the proper way to free all allocated memory in a returned VARIANT? Any suggestions on how I can further analyse the problem?

Thanks
Kevin M. Reilly