If the testing is too much hassle, just stick with 4.3.1.
After all, you know it works.
Sky writes:
OK folks, I did set up 431 as a frugal install and upgraded SeaMonkey.That's exactly what I'm going to do.
I'll do a frugal install and add Shinobar's Seamonkey update .sfs.
On the first try at Pupdial on the new setup, Pupdial connected with no issues.
But, then on the subsequence reboots and power ups, Pupdial failed with same error, modem not found on the tty port - "invalid argument".
It appears that WvDial.conf file works on the first time it is initialized by a system.
Then it appears that something gets over written and the original settings disappear.
If I load a Live CD with no save file then the Pupdial works.
If I create a save file then the next time I boot the OS and initiate Pupdial, Pupdial fails.
Unless, someone sees the answer to this, I have to stop working on the issue. I've done all I can to make it work.
Thank you everyone for your input.