I have tried upgrading 6.1 to 6.1a and uninstalling 6.1a and re-installing from 6.1a media after deleting the Winpoint.ini file.

I get a similar failure when I run a PDS Test from Point Administrator. Here is the event log that was generated:

Event Type:     Error
Event Source:   Application Error
Event Category: None
Event ID:       1000
Date:           6/12/2008
Time:           2:33:31 PM
User:           N/A
Computer:       PWAKEFIELD06
Description:
Faulting application pdsconnect.exe, version 6.1.971.422, faulting module kernel32.dll, version 5.1.2600.3119, fault address 0x00012a5b.

For more information, see Help and Support Center at http://go.microsoft.com/fwlink/events.asp.
Data:
0000: 41 70 70 6c 69 63 61 74   Applicat
0008: 69 6f 6e 20 46 61 69 6c   ion Fail
0010: 75 72 65 20 20 70 64 73   ure  pds
0018: 63 6f 6e 6e 65 63 74 2e   connect.
0020: 65 78 65 20 36 2e 31 2e   exe 6.1.
0028: 39 37 31 2e 34 32 32 20   971.422
0030: 69 6e 20 6b 65 72 6e 65   in kerne
0038: 6c 33 32 2e 64 6c 6c 20   l32.dll
0040: 35 2e 31 2e 32 36 30 30   5.1.2600
0048: 2e 33 31 31 39 20 61 74   .3119 at
0050: 20 6f 66 66 73 65 74 20    offset
0058: 30 30 30 31 32 61 35 62   00012a5b
0060: 0d 0a                     ..