MDBT42 http module using sim808

Hello,

I'm using MDBT42 flashed with the latest firmware (2v08) and I'm experiencing a strange behavior with http module.
After everything initialized using require('SIM900') I got ~1300 free memory and then I started getting \posting data from\to a server every 30 seconds and after the first successful response and starting from the second request I'm getting this error but I'm still getting successful responses...

Uncaught Error: 0, CLOSED already registered
 at line 1 col 44
if(m[a])throw Error(a+" already registered");m[a]=d
                                           ^
in function "registerLine" called from line 2 col 432
...;g[a]=void 0;l=!1;return""});else return g[a]=void 0,""
                              ^
in function "c" called from line 1 col 25
e=void 0;var u;c&&(u=c(t))?(e=k,c=u):clearTimeout(h);void 0=...
                        ^
in function "e" called from line 2 col 16
k=!0);k||e&&e(h)}b=b.substr(a+1);if(k&&f)return d("");"\n"==...
               ^
in function called from system

... while the free memory decrease every request.

FREE MEMORY - 851
FREE MEMORY - 724
FREE MEMORY - 713
...
...
FREE MEMORY - 173
FREE MEMORY - 165
FREE MEMORY - 158
FREE MEMORY - 149
FREE MEMORY - 146
FREE MEMORY - 143
FREE MEMORY - 138
FREE MEMORY - 134

After a couple of minutes I got those errors:

ERROR: Error processing Serial data handler - removing it.
Execution Interrupted during event processing.
New interpreter error: CALLBACK,MEMORY
New interpreter error: BUFFER_FULL
[
  "BUFFER_FULL",
  "CALLBACK",
  "LOW_MEMORY",
  "MEMORY"
 ]

The issue is the same using GET and POST.

Am I doing it wrong?
Is there any better way to do this interval thing?

Here is the full code for my trials.

Thank you.

let sim={};
let m;

function onInit(){
  E.setConsole("Bluetooth");

  setTimeout(() => {
    Serial1.setup(115200,{rx:D8,tx:D6});
  }, 1*1000);
}

function initGPRS(){
  setTimeout(()=>{
    sim.gprs = require('SIM900').connect(Serial1, null, (err)=>{
      if (err) throw err;
      cntGPRS((ip)=>{
        console.log(ip);
        console.log("Error Flags", E.getErrorFlags());
        m = process.memory().free;
        console.log("==========\r\nFREE MEMORY BEFORE STARTING REQUESTS:", m, "\r\n==========\r\n");
        setInterval(()=>{
          testGet1();
          //testGet2();
          //testPost();
        }, 30*1000);
      });
    });
  }, 5*1000);
}

function cntGPRS(cb){
  setTimeout(()=>{
    sim.gprs.connect('', '', '', (err)=>{
      if (err) throw err;
      setTimeout(()=>{
        sim.gprs.getIP((err, ip)=>{
          if (err) throw err;
          if (cb) cb(ip);
        });
      }, 5*1000);
    });
  }, 5*1000);
}

function testGet1(){
  if(!sim.http){
    sim.http = require("http");
  }
  try{
    sim.http.get('http://www.pur3.co.uk', (res)=> {
      let content = "";
      res.on('data', (d)=> {
        content+=d;
      });
      res.on('close', ()=>{
        //console.log(content);
        console.log("Got Response with statuscode:", res.statusCode);
        console.log("Error Flags", E.getErrorFlags());
        m = process.memory().free;
        console.log("==========\r\nFREE MEMORY - GET1", m, "\r\n==========\r\n");
      });
    }).on('error', (e)=>{
      console.log("ERROR:", e);
      console.log("After ERROR GET", m);
    });
  }catch(e){
    console.log("ERROR http.get:", e);
  }
}

function testGet2(){
  require("http").request({
    "host":"http://www.pur3.co.uk",
    "path":"/",
    "method":"GET",
  }, (res)=> {
    let content = "";
    res.on('data', (d)=>{ content+=d;});
    res.on('close', (d)=>{
      //console.log(content);
      console.log("Got Response with statuscode:", res.statusCode);
      console.log("Error Flags", E.getErrorFlags());
      m = process.memory().free;
      console.log("==========\r\nFREE MEMORY - GET2", m, "\r\n==========\r\n");
    });
  }).end();
}

function testPost(){
  postJSON({postURL:"http://www.pur3.co.uk", data: {d:7}, callback: (d)=>{
    if(d) console.log("Response:", d);
    console.log("Error Flags", E.getErrorFlags());
    m = process.memory().free;
    console.log("==========\r\nFREE MEMORY - POST", m, "\r\n==========\r\n");
  }});
}

function postJSON(params) {
  if(!sim.http){
    sim.http = require("http");
  }
  try{
    setTimeout(()=>{
      content = JSON.stringify(params.data);
      let options = url.parse(params.postURL);
      options.method = 'POST';
      options.headers = {
        "Content-Type":"application/json",
        "Content-Length":content.length
      };
      let req = sim.http.request(options, (res)=>{
        let content = "";
        res.on('data', (d)=>{ content+=d; });
        res.on('close', (d)=>{
          console.log("Got Response with statuscode:", res.statusCode);
          params.callback();
        });
      });
      req.on('error', (e)=>{ params.callback(e);});
      req.end(content);
    }, 5*1000);
  }catch(e){
    console.log(e);
  }
}