C++ Skipping cin statement. going into infinite loop

Question

For some reason, it goes into the cin statement the first time but then skips it every other time in this code. After running it a few times, I realized it goes into the default case for some reason without even asking for the user input. Why?

Here's the code. It's a menu with a huge switch statement. The functions inside the switch statements aren't relevant here since it's just the overall loop.

int main()
{
    Document* myDocs = new Document[10];
    int docCount = 0;
    bool menu = true;
    int userInput = 0;

    while ( menu == true )
    {
        //int userInput = 0; 
        userInput = 0;
        cout << "----------------MENU----------------" << endl << endl;
        cout << " --------(1) LOAD DOCUMENT (1)--------- " << endl << endl;
        cout << "--------(2) OUTPUT DOCUMENT (2)--------" << endl << endl;
        cout << " --------(3) ANALYZE DOCUMENT (3)-------- " << endl << endl;
        cout << " ------(4) COMPARE TWO DOCUMENTS (4)------ " << endl << endl; 
        cout << " ----------(5)  ENCRYPT  (5)---------- " << endl << endl; 
        cout << "-----------(6)  DECRYPT  (6)----------" << endl << endl;
        cout << "-------------(7) EXIT (7)--------------" << endl << endl; 

        cin >> userInput;
        string docName;
        string outputLoc;

        switch (userInput)
        {
        case 1:
            // Function
            break;
        case 2:
            // Function
            break;
        case 3-8:
            // Function
            break;
        default:
            break;
        }

Basically, I first enter the first userinput. Let's say I enter 1. Then it goes into case 1. But then after it gets out of case 1, it goes into an infinite loop that keeps displaying the menu. Shouldn't it stop at the cin statement? That's what I dont understand.

EDIT::

Case 1 is the primary one i'm worried about since I'm trying them 1 by and 1 and case 1 doesn't work. This is the full code for case 1:

    case 1: // Load Document
        {
            string inputLoc;
            cout << "Please input the document name:" << endl;
            cin >> docName;
            myDocs[docCount].setName(docName);
            myDocs[docCount].id = docCount;
            cout << "Input Location: " << endl;
            cin >> inputLoc; 
            myDocs[docCount].loadDocument(inputLoc);
            docCount++;
            break;
        }

I'm starting to speculate there is something wrong with my loadDocument function. Here is the code for that:

    void Document::loadDocument(string name)
    {
ifstream myFile(name);
int numOflines = 0; 
string theLine;
char words; 

while (myFile.get(words))
{
    switch (words)
    {
    case '.':
        numOflines++;
        break;
    case '?':
        numOflines++;
        break;
    case '!':
        numOflines++;
        break;
    }
}

lineCount = numOflines; 
setLineCt(numOflines);
arr = new Line[lineCount];
myFile.close();
char theChar;
ifstream myFile2(name);
int key = 0;

if (myFile2.is_open())
{
    for ( id = 0; id < lineCount; id++ )
    {           
        while (myFile2>> noskipws>>theChar && theChar != '.' && theChar != '!' && theChar != '?') // Changed from || to &&
        {
            //myFile2>> noskipws >> theChar;
            theLine[key] = theChar;
            key++;
        }           

        myFile2>>theChar;

        arr[id].setStr(theLine); 
    }
}
}

Basically I'm trying to load the document and store the word count and line count from it. Is there something wrong in it?