Inaccessable files, how do I retrieve them?

I have a problem with H & R Block and their software Taxcut 2005, after three on-line chat sessions I still do not have a solution to my problem, hence I am looking wider afield. I am locked out of tax files that I need, now. I have used H & R Block Taxcut for many years, yes it's not perfect, but no PC software attains that state.

I run W2kPro on an HP Professional workstation, model number A1280C. This is a twin-processor machine with 4GB of memory, dual 36GB SCSI 160 hard-drives, SCSI 160 tape drive, ATAPI CD-RW drive. All program files are stored on my C:\ drive; all data files are stored on a separate F:\ drive.

Recently I had a need to retrieve files from my FY2005 tax return. On trying to access those files, for every file I selected I received the error message:

"Invalidcommand line syntax"
"(see CommandlineImpl::initOptions)"

The advice from H & R Block chat line was "delete the Taxcut program files and restore the files from the original disk". I had been down that road already, it does not solve the problem. I have tried erasing the program files, repairing the registry with MS Regclean, followed by RegOpt to tidy-up the registry and ended up with running MS Scandisk just for insurance. After the clean-up Taxcut 2005 was reloaded from the CD and updated from the H & R web-site. All very clever, but it did not fix the problem. All of my stored Taxcut files for other years operate correctly, so this is a problem unique to that version of the software.
I can run the Taxcut 2005 program, create a file, save it then find myself locked out with that same pestilential error message!

I see from Google that others have experienced exactly the same problem, but I could not find a published solution. Hence I'm asking if any noble geeks can offer advice that works!