Aligning column data in a scrollable table

[SonxQ7]

I have the following table

<!-- Static Headers -->
<table style="width: 620px">
	<thead>
		<tr>
			<td colspan="3" width="15"></td>
		</tr>
		<tr valign="top" class="results_headings">
			<td width="35%">Force Number</td>
			<td width="35%">Name</td>
			<td width="30%">Required Qual Code</td>
		</tr>
	</thead>
</table>

<!-- Scrollable Area -->
<div class="scrollable">
	<table class="memberlist">
		<c:forEach items="${members}" var="mem" varStatus="status">
			<tr>
				<td width="35%"><c:out value="${mem.forceCode}" /></td>
				<td width="35%"><c:out value="${mem.fullName}" /></td>
				<td width="30%"><c:out value="${mem.reqQualCode}" /></td>
			</tr>
		</c:forEach>
	</table>
</div>

The first table produces headings, and the next is a scrollable table ... The challenge is the columns in the scrollable table shift when there' no srcoll bar! Any idea on how to keep the results within the same length in both cases (scroll-bar & No scrollbar)