Very strange behaviour with cfhttp an cfhttpparam - coldfusion

Question

Happy New Year,
The New Year found me wrestling with a coding problem. I am using ColdFusion and as for CFML engine “openBD”. I have a CFC that handles requests for the search engine that I use (SOLR search engine). I am “feeding” that CFC with some arguments. The CFC performs as it should. But when I am trying to pass a specific argument (#apofasi_taxonomy #) the CFC doesn’t returns nothing (If I pass the above argument directly to the search engine –not using CFC- I can see return/search results)
Part of CFC:
<cffunction name="searchP" access="remote" returnFormat="json">
<cfargument name="q" type="string" default="" required="yes">
<cfargument name="apofasi_taxonomy" type="string" default="apofasi_taxonomy:(*)" required="yes">
<cfargument name="apofasi_tmima" type="string" default="apofasi_tmima:(*)" required="yes">
<cfargument name="apofasi_date" type="string" default="apofasi_date:(*)" required="yes">
<cfargument name="apofasi_number" type="string" default="apofasi_number:(*)" required="yes">
<!---<cfargument name="apofasi_taxonomy" type="string" default="*">
<cfargument name="apofasi_tmima" type="string" default="*">
<cfargument name="apofasi_date" type="string" default="*">
<cfargument name="apofasi_number" type="string" default="*">--->
<cfset theUrl = 'http://localhost/solr/areios_pagos/select/?'>
<cfhttp method="get" url="#theUrl#" port="8090" result="rs" username="abcd" password="********">
<cfhttpparam type="url" name="q" value="#q#">
<cfhttpparam type="url" name="fq" value="#apofasi_taxonomy#+#apofasi_tmima#+#apofasi_date#+#apofasi_number#">
<!---<cfhttpparam type="url" name="fq" value="apofasi_taxonomy:(3068 || ΠΟΙΝΙΚΕΣ) AND apofasi_date:(2010)">--->
<!---<cfhttpparam type="url" name="fq" value="apofasi_taxonomy:(3068) AND apofasi_date:(*) AND apofasi_number:(*)">--->
<cfhttpparam type="url" name="rows" value="120">
<cfhttpparam type="url" name="wt" value="json">
<cfhttpparam type="url" name="sort" value="score desc">
<cfhttpparam type="url" name="hl" value="true">
<cfhttpparam type="url" name="hl.fl" value="content,title">
<cfhttpparam type="url" name="fl" value="grid_title,title,url,ida,model,search_tag,solr_id">
<cfhttpparam type="url" name="f.content.hl.alternateField" value="content">
<cfhttpparam type="url" name="hl.maxAlternateFieldLength" value="800">
</cfhttp>
Notice that the search engine consumes urls like:
http://localhost/solr/areios_pagos/select/?q=blahblah&fq=apofasi_taxonomy:(3068)+ apofasi_tmima:(Α || Ζ)+ apofasi_date:(2007 || 2012)+apofasi_number:(666)
What I have checked until now: The arguments that I am passing to CFC are 100% OK (from html), I have double-checked if the search engine can consume the above url syntax. But I have noticed a very strange behavior. When I exclude the #apofasi_taxonomy# or #apofasi_tmima# arguments from the url completely the CFC is working (it returns results).
The values that #apofasi_taxonomy# argument takes are: apofasi_taxonomy:(ΠΟΙΝΙΚΕΣ), apofasi_taxonomy:(ΠΟΛΙΤΙΚΕΣ), apofasi_taxonomy:(3068) or apofasi_taxonomy:(ΠΟΙΝΙΚΕΣ || 3068), apofasi_taxonomy:(ΠΟΙΝΙΚΕΣ || ΠΟΛΙΤΙΚΕΣ) and so on.
I have noticed one more thing, #apofasi_taxonomy# argument is working with the values below: apofasi_taxonomy(ΠΟΙΝΙΚΕΣ), apofasi_taxonomy:(ΠΟΛΙΤΙΚΕΣ)and apofasi_taxonomy:(ΠΟΛΙΤΙΚΕΣ || ΠΟΙΝΙΚΕΣ) but it is not working for apofasi_taxonomy:(3068), apofasi_taxonomy:(ΠΟΛΙΤΙΚΕΣ || 3068), apofasi_taxonomy:(ΠΟΛΙΤΙΚΕΣ || 3068) or apofasi_taxonomy:(ΠΟΛΙΤΙΚΕΣ || ΠΟΛΙΤΙΚΕΣ || 3068). Isn’t that weird?
The values that #apofasi_tmima# argument takes are: Α || Α1 || Α2 || Β || Β2 || Γ || Δ || Ε || ΣΤ || Ζ || ΟΛΟΜΕΛΕΙΑ e.g. apofasi_tmima(Β || Β2 || ΟΛΟΜΕΛΕΙΑ).
Keep in mind that the above values are in Greek language.
Is there anyone out there that can help?
With respect,
Tom
edit: Moved requested XML provided in comments to the question
<fieldType name="text_areios_pagos" class="solr.TextField" positionIncrementGap="100">
<analyzer type="index">
<tokenizer class="solr.StandardTokenizerFactory"/>
<filter class="solr.StopFilterFactory" ignoreCase="true" words="lang/stopwords_en.txt" enablePositionIncrements="true"/>
<filter class="solr.LowerCaseFilterFactory"/>
<filter class="solr.EnglishPossessiveFilterFactory"/>
<filter class="solr.StopFilterFactory" ignoreCase="true" words="lang/stopwords_el.txt" enablePositionIncrements="true"/>
<filter class="solr.GreekLowerCaseFilterFactory"/>
<filter class="solr.GreekStemFilterFactory"/>
<filter class="solr.KeywordMarkerFilterFactory" protected="protwords.txt"/>
<filter class="solr.PorterStemFilterFactory"/>
</analyzer>
<analyzer type="query">
<tokenizer class="solr.StandardTokenizerFactory"/>
<filter class="solr.SynonymFilterFactory" synonyms="synonyms.txt" ignoreCase="true" expand="true"/>
<filter class="solr.StopFilterFactory" ignoreCase="true" words="lang/stopwords_en.txt" enablePositionIncrements="true"/>
<filter class="solr.StopFilterFactory" ignoreCase="true" words="lang/stopwords_el.txt" enablePositionIncrements="true"/>
<filter class="solr.GreekLowerCaseFilterFactory"/>
<filter class="solr.GreekStemFilterFactory"/>
<filter class="solr.LowerCaseFilterFactory"/>
<filter class="solr.EnglishPossessiveFilterFactory"/>
<filter class="solr.KeywordMarkerFilterFactory" protected="protwords.txt"/>
<filter class="solr.PorterStemFilterFactory"/>
</analyzer>
</fieldType>

Answer 1

You may have to add a charset attribute to your cfhttp tag
<cfhttp ... charset="ISO-8859-7" ...