Problem with program hanging - SQLServer issue?

I'm having a problem in my VB6 program in that it will "stall" or
"hang" (like it's in an endless loop) from time to time, seemingly at
random. I am highly suspicious that the problem is with some async
queries the program makes to an SQL Server (2000) database.

I'm using the following code in various places in the program:

Public WithEvents SQLServerCN As ADODB.Connection

CS$ = "Provider=SQLOLEDB.1; Persist Security Info=False;"
CS$ = CS$ & "UID=MyUserID; pwd=MyPassword;"
CS$ = CS$ & "Initial Catalog=MyDatabaseName;"
CS$ = CS$ & "Data Source=TheServerName"

Set SQLServerCN = New ADODB.Connection
SQLServerCN.CursorLocation = adUseClient
SQLServerCN.ConnectionTimeout = 3
SQLServerCN.Open CS$, , , adAsyncConnect


I execute some stored procedures like so:
Dim rsX As New ADODB.Recordset
rsX.Open "LookupBarcode 12345678", SQLServerCN, adOpenStatic,
adLockReadOnly, adAsyncExecute

And, like this:
SP$ = "CheckOrder @OrderNumber=" & CON$ & ",@Status=0"
SQLServerCN.Execute SP$, , adCmdText

And a couple of SQL statements like so:
SQL$ = "UPDATE MyTable SET lStatus=110, lDestinationID=123 WHERE
strBarcode='12345678';"
SQLServerCN.Execute SQL$, , adCmdText + adExecuteNoRecords

In the SQLServerCN_ExecuteComplete event, I check for errors and do
various other things, depending on which stored procedure or statement
was executed.

It's all pretty straight-forward and 99.9% of the time it seems to
work ok.

Do any of you have any ideas that I might investigate as to what might
be happening that would cause my program to literally stop executing
for a few seconds? I thought the fact that I was doing things
asynchronously would allow me to keep running even if a problem was
encountered on the server side - is this not true?

Any advice?

Thanks

Martin
.