Here is the short of it.  I have code trying to remove a substring from a field on deletion of a child record (the creation of each child record actually adds a string to a field on the parent record, bascially a way to have a roll-up summary of text).  Anyhow I need to REMOVE that text if a child record is deleted.  Here is the code that is giving me trouble:

		For(Opportunity o :opps){
				system.debug('Opp Looking at ------------------------------>  ' + o.ID);
			For(Opportunity_Product__c oP :oppProds){
				system.debug('Opp Prod Looking at ------------------------------>  ' + oP.ID);				
				If(oP.Opportunity_Name__c == o.ID){				
					string PSNameAndID = oP.Product_Service__r.Name;					
					system.debug('zOppProd4RuleFormulas before edit ------------------------------>  ' + o.zOppProd4RuleFormulas__c);
					system.debug('P/S Name ------------------------------>  ' + PSNameAndID);			
					o.zOppProd4RuleFormulas__c.replace(PSNameAndID, '');
					system.debug('zOppProd4RuleFormulas AFTER edit ------------------------------>  ' + o.zOppProd4RuleFormulas__c);																		
				}
			}
			oppsToUpdate.add(o);	
		}		
		update oppsToUpdate; 

Here is the output from a test of that:

36]|DEBUG|Opp Looking at ------------------------------>  006g0000001szvxAAA
11:31:47.129 (129161000)|SYSTEM_METHOD_EXIT|[36]|System.debug(ANY)
11:31:47.129 (129173000)|SYSTEM_METHOD_ENTRY|[37]|LIST<Opportunity_Product__c>.iterator()
11:31:47.129 (129207000)|SYSTEM_METHOD_EXIT|[37]|LIST<Opportunity_Product__c>.iterator()
11:31:47.129 (129217000)|SYSTEM_METHOD_ENTRY|[37]|system.ListIterator.hasNext()
11:31:47.129 (129229000)|SYSTEM_METHOD_EXIT|[37]|system.ListIterator.hasNext()
11:31:47.129 (129263000)|SYSTEM_METHOD_ENTRY|[38]|String.valueOf(Object)
11:31:47.129 (129290000)|SYSTEM_METHOD_EXIT|[38]|String.valueOf(Object)
11:31:47.129 (129303000)|SYSTEM_METHOD_ENTRY|[38]|System.debug(ANY)
11:31:47.129 (129312000)|USER_DEBUG|[38]|DEBUG|Opp Prod Looking at ------------------------------>  a1hg00000004DG4AAM
11:31:47.129 (129319000)|SYSTEM_METHOD_EXIT|[38]|System.debug(ANY)
11:31:47.129 (129349000)|SYSTEM_METHOD_ENTRY|[39]|Id.compareTo(Id, Boolean)
11:31:47.129 (129380000)|SYSTEM_METHOD_EXIT|[39]|Id.compareTo(Id, Boolean)
11:31:47.129 (129511000)|SYSTEM_METHOD_ENTRY|[42]|System.debug(ANY)
11:31:47.129 (129540000)|USER_DEBUG|[42]|DEBUG|zOppProd4RuleFormulas before edit ------------------------------>  Sabre PMS; XX Hardward Solution w/Software Licensing - a0Jg00000008yzWEAQ; XX Hardward Solution w/Software Licensing - a0Jg00000008yzWEAQ
11:31:47.129 (129550000)|SYSTEM_METHOD_EXIT|[42]|System.debug(ANY)
11:31:47.129 (129566000)|SYSTEM_METHOD_ENTRY|[43]|System.debug(ANY)
11:31:47.129 (129588000)|USER_DEBUG|[43]|DEBUG|P/S Name ------------------------------>  XX Hardward Solution w/Software Licensing
11:31:47.129 (129596000)|SYSTEM_METHOD_EXIT|[43]|System.debug(ANY)
11:31:47.129 (129661000)|SYSTEM_METHOD_ENTRY|[45]|System.debug(ANY)
11:31:47.129 (129686000)|USER_DEBUG|[45]|DEBUG|zOppProd4RuleFormulas AFTER edit ------------------------------>  Sabre PMS; XX Hardward Solution w/Software Licensing - a0Jg00000008yzWEAQ; XX Hardward Solution w/Software Licensing - a0Jg00000008yzWEAQ
11:31:47.129 (129695000)|SYSTEM_METHOD_EXIT|[45]|System.debug(ANY)
11:31:47.129 (129740000)|SYSTEM_METHOD_ENTRY|[37]|system.ListIterator.hasNext()
11:31:47.129 (129755000)|SYSTEM_METHOD_EXIT|[37]|system.ListIterator.hasNext()
11:31:47.129 (129793000)|SYSTEM_METHOD_ENTRY|[49]|LIST<Opportunity>.add(Object)
11:31:47.129 (129854000)|SYSTEM_METHOD_EXIT|[49]|LIST<Opportunity>.add(Object)
11:31:47.129 (129868000)|SYSTEM_METHOD_ENTRY|[35]|system.ListIterator.hasNext()
11:31:47.129 (129881000)|SYSTEM_METHOD_EXIT|[35]|system.ListIterator.hasNext()
11:31:47.129 (129942000)|DML_BEGIN|[51]|Op:Update|Type:Opportunity|Rows:1

Why is it not removing that string like it is supposed to?  I have tried setting the field to a string variable and then trying to use the replace() method, but still no dice.  What is the problem here?

Thanks,

Jeremy Stender