asterisk users - Dec 2004 - PRI got event: HDLC Bad FCS

I'm running asterisk 1.0.3 and seeing occasional messages on the 
asterisk console that say:

Dec 18 09:09:55 NOTICE[26411]: chan_zap.c:7381 pri_dchannel: PRI got 
event: HDLC Bad FCS (8) on Primary D-channel of span 1

or

Dec 18 09:25:46 NOTICE[26411]: chan_zap.c:7381 pri_dchannel: PRI got 
event: HDLC Abort (6) on Primary D-channel of span 1

They don't see to have a noticeable impact but the server is only in 
test so far.  Is this something I should worry about before the server 
goes into production?  I couldn't find much of anything in searching the 
web and in looking at the code, it's not obvious if this is a problem or 
not.

Thanks,
Adam