Might find some information at: http://www.amsat-dl.org/

If you want to work the LEO's then a transceiver that covers two meters and 70 cm.  All mode would be best, some off hand are the Kenwood TS-2000 (can run duplex on the LEO's) and the Yeasu FT-847 One can work a few FM satellites with a dual band HT, UO-14 and SO-50, but like the other post only one QSO at a time.  There are a few linear satellites, FO-29 is active and also early this year AO-7 came back to life after twenty some years of thought to be SK.  But it works only in sunlight and the mode can change from orbit to orbit, still has a 10 meter  output.  RS-15 has been lousy and very hard to work barely hear the beacon and if you can work someone your really lucky.  Two single band satellites, with the ISS Packet supposed to be coming back on line after almost 9 months off the air, it maybe worked with a ground plane antenna and about 10 Watts.  Check or subscribe to the AMSAT-BB for news.  Also there is PCSAT on 145.828 but is not doing well as the batteries are going and it only is truned on in sunlight.  Both ISS and PCSAT are APRS Packet digipeaters.  AMSAT: www.amsat.org

Yes have Winpack installed on Windows XP Home version, runs great.  Are you using a TNC or the soundcard?  If using soundcard, you also need to run AGWPE before loading Winpack.  There is a Winpack Yahoo group and Roger the author answers a lot of the questions posted about Winpack:  http://groups.yahoo.com/group/winpack/

Not sure why the older RASCAL works and not the new one? Must be the configuration? I have a home brew interface that has been used with the IC-706 and the IC-746 (non Pro) so not sure why only one of two work. Maybe softwate set up?  Souncard settings?  Is there software that is used with the new RASCAL.  Looked at the RASCAL a few years back and decided I could make my own version, looked pretty straight forward, audio in and out and PTT function.

Have you tried to email your state SCM, if any one would know he should, maybe.  Some times the stations are listed in repeater directories, but Packet is not very active here except for a DX Cluster and APRS digipeater.  Those who have a APRS station might know of any regular Packet nodes, I think the "National" Packet frequency used to be 145.010?

Serial port, depends on if your using RTS which is the most common at pin 7 on the DB-9 connector and ground at pin 5, if using DTR then pin 4 and pin 5.  Serial port comm settings default at Com 1, 9600, 8 none 1, RTS or DTR set to PTT, no hardware flow, set always off on the output your not using as DTR would be always off on default.  I believe that AGWPE sets these values as a default, but would be worth checking.  

Might check AGWPE: http://www.elcom.gr/sv2agw/inst.htm The non pro one works pretty good on VHF, have never tried it on HF.  There is a Yahoo group that is pretty helpful: http://groups.yahoo.com/group/SV2AGW/

Also forgot the ground for Pin 11 is Pin 12.

Yes using the rear ACC2 connector is the best way to interface.  Have home made interface, but they all do the same, interface the rig and computer. ACC2 Din connector on the 570 - Receive audio output Pin 3, routes through to the interface to the line input of the sound card.  Pin 4 Ground for Pin3.  Pin 9 is the PTT from the interface from the computers serial com port. Pin 11, Transmit audio input routed through the interface from the speaker output of the sound card. Here is a link to the TS-570 Manual, see page 62 for the ACC 2 pinout: http://www.kenwood.net/ then Amateur Radio, on the left of the page "Jump to, Manuals" (Current Models) find the pdf for the 570, requires Acrobat Reader which is a free download from Adobe.

Check the Yahoo egroup on the TMD700A: http://groups.yahoo.com/group/TMD700A/
They might have the answer.

Have not tried the TS-2000 in the internal Packet mode for DX Cluster for APRS ;-).  But as the other post lists, UI-View works very well and also download the USA maps that are on another site listed at the UI-View software site: http://www.ui-view.com/ Be sure to have the TS-2000 in the Packet mode Menu 55, but not the auto Cluster mode ;-) then start UI-View or the other APRS prgram listed.

Check the TAPR site, they seem to be the experts on APRS: http://www.tapr.org/tapr/index.html

Might post this question on the Yahoo egroup TMD700A: http://groups.yahoo.com/group/TMD700A/

If the TH-D7A is like the TH-F6A, check Menu for PC setting, should be set to "PC".  Set the radio to "PC" then power up the computer.  ON the TH-F6A Menu #9 sets the "PC"  mode or external speaker mike.  If you have it set on PC the external mike will not work, you will hear sound though.  

Don,  Might check "The Antenna Guru" L. B. Cebik, W4RNL site: http://www.cebik.com/radio.html  He has lots of antenna information plus at the bottom there are links to "other antenna sites".