Selenium - Navigation gets stuck after clicking a drop down (prior to an iframe switch) - selenium

Question

The code clicks and pops up an overlay (successful). I am able to switch to iframe (using the driver.switchTo().frame(2)). Once selecting an element and clicking the Accept button, the overlay closes. Now I switch back to the main page using driver.switchTo().defaultContent(). The problem occurs soon after the code clicks a dropdown in the main page. This dropdown is not the typical Select or Option type (Select() or <option>). The elements are listed in a <table>.
There is no error displayed in the console but the program hangs. It stops the navigation after clicking the drop down and then no response.
Please find the html portion:
<input type="hidden" name="ctl00$cph$ctl02$TEST$FORM$ctl06$ctl32$ctl01$ctl03"
id="ctl00_cph_ctl02_TEST_FORM_ctl06_ctl32_ctl01_ctl03" />
<input type="hidden" name="ctl00$cph$ctl02$TEST$FORM$ctl06$ctl32$ctl01$ctl04"
id="ctl00_cph_ctl02_TEST_FORM_ctl06_ctl32_ctl01_ctl04" value="-1" />
<input type="hidden" name="ctl00$cph$ctl02$TEST$FORM$ctl06$ctl32$ctl01$ctl05" />
<input type="hidden" name="ctl00$cph$ctl02$TEST$FORM$ctl06$ctl32$ctl01$ctl06" />
<div id="ctl00_cph_ctl02_TEST_FORM_ctl06_ctl32_ctl01_outerFrame"
class="DropdownOuterContainer theme2 boarderA font7 shadow1" style="display:none;">
<div id="ctl00_cph_ctl02_TEST_FORM_ctl06_ctl32_ctl01_innerFrame"
class="DropdownInnerContainer" style="z-index:99;">
<table id="ctl00_cph_ctl02_TEST_FORM_ctl06_ctl32_ctl01_tbl"
class="DropdownItemContainer" list="120">
<tr class="">
<td value="" index="0" title="">
</td>
<td class="BorderCell"></td>
</tr>
<tr class="">
<td value="Act1" index="1" plid="1001">Act1</td>
<td class="BorderCell"></td>
</tr>
<tr class="">
<td value="Act2" index="2" plid="1002">Act2</td>
<td class="BorderCell"></td>
</tr>
<tr class="">
<td value="Act3" index="3" plid="1003">Act3</td>
<td class="BorderCell"></td>
</tr>
<tr class="">
<td value="Act4" index="4" plid="1004">Act4</td>
<td class="BorderCell"></td>
</tr>
</table>
In the code I am trying to select an option 'Act1' using the below statements. Note that only the first line executes, i.e, it clicks the drop down but then it doesn't move forward to the next step, where the selection happens.
driver.findElement(By.xpath(".//*[#id='ctl00_cph_ctl02_TEST$FORM_ctl06_ctl32_ctl01']")).click();
driver.findElement(By.xpath(".//*[#id='ctl00_cph_ctl02_TEST$FORM_ctl06_ctl32_ctl01_tbl']/tbody/tr/td[1][contains(text(),'Act1')]")).click();