You need to decide how you intend to read/update the data.  If you are doing this is VB.net see a tool like LLBLGEN (http://www.sd.nl/software/)  If you are using VB 6 see http://users.quista.net/thealey/download.htm (CodeGEN) for some samples on how to do this.  I'm pretty sure your problem #1 has to do with with cursor type when you open the recordset (The default is "adOpenStatic" which is a disconnected recordset. Records added/modified/deleted to the DB at the same time by another user/process are not accessible in this cursor type.)  Both the tools I mentions will generate both Stored procs and VB code to call these procs which is great even if only used for sample code.

As for question 2  256 M RAM is really borderline I would definitely ask for a bigger box or least a substantial memory upgrade (3-6 times what you have).  Use the Memory counters in Performance Monitor to check for bottlenecks but I can almost guarantee that more memory will get you better performance.