Twittering about spam

I joined Twitter over a year ago, sent my first tweet and felt proud! However that was the extent of my tweeting experience. Now my account has become more active as I interact with students from my class and as I post tweets to do with social networking. I have found that more of my friends are on twitter than I thought and I am  communicating with them and I am tweeting support to Australian athletes in London for the Olympics.
However, it has not been all smooth sailing, actually I am finding things about Twitter quite frustrating. I was happily tweeting away adding tags to my tweets that would allow my classmates to search from my tweets. However after a while I began to notice that some of my tweets were not being captured in a search. Any tweet with a URL link would not show up in the #tag search. This was frustrating as I had felt that these tweets with links were important articles that I wanted to share, yet unless my classmates specifically subscribed to my tweets, they wouldn't be able to see these tweets.
Unsure of what was going on as all my setting seemed fine I went to Google to investigate and found that there were other users that have reported other problems, but had no solution. I searched Twitter help and information about why tweets weren't appearing, but none of they quite fit my situation of why only some of my tweets were missing from search.
This is when it was suggested to me that perhaps it has to do with spam protection. My account had very little activity and suddenly I was tweeting a lot and using links. It could look a little suspicious. One of the ways in which twitter looks at spamming is “If your updates consist mainly of links, and not personal updates” I was wondering if Twitters spam protection was stopping these links from coming up in search.
A question to Twitter support suggested that “The best course of action is to continue tweeting, re-tweeting and mentioning others to gain resonance amongst your followers” So it seems that I have to gain authenticity as a Tweeter for all my tweets to show up in #tag searches. It seems disappointing that spammers do make it difficult for everyone else.  This raises the question of how this need to gain resonance amongst followers affects a library that is just starting to tweet and wants to link to their library site.