This appears to be a very minor bug, which results in the following exception being raised when executing a test having emptied the timeout property field: 

'Cannot assign '' to property 'Timeout' of type 'Int64''

Steps to reproduce:

1) Specify a custom timeout property (under the Settings tab) for a Http Request;
2) Save;
3) Empty timeout property field;
4) Save;
5) Run test;

Expected result: Test succeeds;
Actual result:  Test fails;

I realise that this is probably something which has already been fixed in the upcoming release, but I thought I'd raise it just in case. I think this is a convenient functionality, as it permits ad hoc raising of the expected response time; but I would like to be able to have it return to the default (currently 2000ms), which I am sure that we will be able to control at a project level for example (or does this exist already?) in some future release.