Hi John,
That's the correct behaviour. For 0.7 apps we don't append a timestamp, it's up to the developer to determine whether they want the browser to cache the request or not. You might be confusing this with API calls, for which we do append a timestamp.
We incorrectly started appending a timestamp parameter for 0.8 makeRequest calls, but this can be removed via:
var params = {};
params[MyOpenSpace.RequestParameters.NO_TIMESTAMP] = true;
What you're probably seeing is caused by the removal of the token from the query string on makeRequest calls, which was also breaking browser cache. Details here:
http://developer.myspace.com/Community/blogs/devteam/archive/2009/03/16/makerequest-token-changes.aspx
In short, we're now correctly allowing developers themselves to determine whether they cache on the browser or not. If you really don't want the browser to cache append a similar timestamp to your URLs, but browser caching, as I'm sure you're aware, can save a lot on bandwidth.
Chad