[Coco] coco1 64K extended basic SN ERROR

[Charlie Pelosi]

I have a 64K coco1 with Extended Color Basic. With some basic programs it gives me a ?SN ERROR but if I simply type RUN again the program runs fine with no error.

One example is the game BUGS found here: http://www.colorcomputerarchive.com/coco/Disks/Games/Bugs%20(Color%20Computer%20Magazine).zip
When I run BUGS.BAS it says ?SN ERROR. (no "in line number", just ?SN ERROR) I type RUN again and the game runs fine. Some experimenting tells me it never gets past the 1st line of the program.

0 CLS0:PCLEAR1:FILES0:CLEAR5,5119:GOTO4

Another example is Jim Gerrie's Dungeon Crawl. 
http://rsp.retrocomputacion.com/games-jim-gerrie-ports-4-of-his-games-to-the-tandy-coco/
When I RUN"CRAWL I get ?SN ERROR IN 0
Entering RUN again and the game runs without the error.
Line 0 reads:
0 PCLEAR1:GOSUB2600:CLEAR1300:DIMA$(15),B$(15),C$(15),D$(24),E$(24),I$(27),D(20,20,2),W$(34):GOTO900

Now, I know the coco3 does not have this issue. Not sure about BUGS but I know Dungeon Crawl starts on the 1st RUN.
What is the issue with the coco1? I will drag out my coco2 and try with that. Perhaps this is a known issue with ECB?

Charlie