Unable to call getTransactionCount when running in Browser network

[filippsen]

Environment/Browser

Version 1.4.3

Description

Unable to call or read back results from web3.eth.getTransactionCount when running in Browser network.

Steps to reproduce

1. Create a new project starting from Hello World template
2. In app.js, change HelloWorld.prototype.getBlockNumber from calling getBlockNumber to getTransactionCount:

HelloWorld.prototype.getBlockNumber = function(cb) {
    this.web3.eth.getTransactionCount("0xa48f2e0be8ab5a04a5eb1f86ead1923f03a207fd", function(error, result) {
        console.error(error);
        console.log(result);
        cb(error, result);
    });
};

3. Deploy
4. Open Show Preview
5. Observe the browser console output

Expected result

Expected it to return a number.

Actual result

Uncaught Error: new BigNumber() not a number: [object Object]

Hints and reference

This could be a problem in "superprovider" and/or when dealing with BigNumber data directly. Missing data converstion?

https://github.com/ethereum/wiki/wiki/JavaScript-API#web3ethgettransactioncount

Requirements

Depends on #343