unable to clear dtc's

hello, i recently got the v4 working for my 95 pontiac bonneville ssei. i am using a cable purchased thur obd diagnostics. it runs thur the usb port on my laptop. (comm 4) everything seems to work ok except when i try to clear the trouble codes. i click on the macro for clear codes and then start aldl. i'm getting checksum error and also echo 232 error. it sends the commands and then the errorrs show up in red. also when i double click the clear codes macro, it displays the clear code letters and in front of it a big exclamation mark. it does this on both macros. one other question. looking at the DTC chart under cel it has false indicated for all the codes. (i have eight showing up) what does this mean? thanks in advance for any help.

Can you tell me the name of the *.xml file (data stream definition) that you are using?

Also, please turn on the menu option: View->Serial I/O, then run the Clear DTC macro again. Copy the I/O text that is displayed and paste it into this thread so I can see what is happening.

The "True/False" entry for CEL means whether the Check Engine Light (CEL) is designed to illuminate when that code is set. If they are all false then that information was not available when the data stream definition was created.

Regards
Paul