John, the reliability concerns for the condition you describe (solder icicles
or spikes)are as follows:

1. Electrical - when conductor-conductor minimum space is violated.
2. Mechanical- when height requirement is violated
3. Possible Intermittent - when icicles break loose and lodge between
component leads or between pads in fine pitch area.

It is a process problem indicator. The area where icicles are showing up may
be getting cooled prior to moving away from solder wave. Look for area
pattern or component dependent relationship. If you will please share your
observations and solution.

Pratap Singh
RAMP Labs
(512) 255-6820