You guys really need to get a competent commenting system: so far, your reliance on typepad plain sucks.
There are a number of good plugins which will allow you to have a serious commenting system, further your own academic goals, and not piss off most people trying to get something out of being here.
Just saying ...
There is no rule against commenting more than 3 times in a thread. Sorry if anyone has gotten this impression.
However, among the 10 "Recent Comments" visible in the sidebar at right, usually no more than 2, rarely 3, and never 4, should be yours. This is meant to ensure no one person dominates a thread; it gives others a chance to respond to others' responses. One-line comments that quickly correct an error may be common-sensically excepted from this rule.
You need not refrain from commenting, just wait a bit.