diff --git a/AdcProtocol.go b/AdcProtocol.go
index 94d7c55..8488c4a 100644
--- a/AdcProtocol.go
+++ b/AdcProtocol.go
@@ -175,21 +175,56 @@ func (this *AdcProtocol) ProcessCommand(msg string) {
 			return
 		}
 
-		uinfo, err := this.handleUserInfo(flags)
-		if err != nil {
-			this.logError(err)
-			return
-		}
-
 		// Log this user in, and associate this SID with this user
 		this.hc.usersMut.Lock()
 		defer this.hc.usersMut.Unlock()
 
-		newNick := uinfo.Nick
-
 		oldNick, sidExists := this.hc.userSIDs[sid]
 
-		handleNewUser := func() {
+		uinfo := UserInfo{}
+		if sidExists {
+			uinfo_lookup, ok := this.hc.users[oldNick]
+			if !ok {
+				// Shouldn't happen
+				this.hc.processEvent(HubEvent{
+					EventType: EVENT_SYSTEM_MESSAGE_FROM_CONN,
+					Message:   fmt.Sprintf("Hub connection corrupted (missing info for SID='%s' nick='%s'), disconnecting", sid, oldNick),
+				})
+				this.hc.Disconnect()
+				return
+			}
+
+			uinfo = uinfo_lookup
+		}
+
+		this.updateUserInfo(&uinfo, flags)
+		newNick := uinfo.Nick
+		if len(newNick) == 0 {
+			this.logError(fmt.Errorf("Zero-length nick for user (SID='%s')", sid))
+		}
+
+		shouldHandleNewUser := false
+		if sidExists && oldNick != newNick {
+			// Nick change = delete all trace of this user first, treat as new
+
+			delete(this.hc.users, oldNick)
+			delete(this.hc.userSIDs, sid)
+			this.hc.processEvent(HubEvent{EventType: EVENT_USER_PART, Nick: oldNick})
+			shouldHandleNewUser = true
+
+		} else if sidExists && oldNick == newNick {
+			// Updating existing user
+			this.hc.users[newNick] = uinfo
+			this.hc.processEvent(HubEvent{EventType: EVENT_USER_UPDATED_INFO, Nick: newNick})
+
+		} else if !sidExists {
+			// User joined
+			shouldHandleNewUser = true
+		}
+
+		//
+
+		if shouldHandleNewUser {
 			// Install this SID as pointing to this nick
 			this.hc.userSIDs[sid] = uinfo.Nick
 
@@ -206,28 +241,10 @@ func (this *AdcProtocol) ProcessCommand(msg string) {
 			}
 
 			// Notifications
-			this.hc.users[newNick] = *uinfo
+			this.hc.users[newNick] = uinfo
 			this.hc.processEvent(HubEvent{EventType: EVENT_USER_JOINED, Nick: newNick})
 		}
 
-		if sidExists && oldNick != newNick {
-			// Nick change = delete all trace of this user first, treat as new
-
-			delete(this.hc.users, oldNick)
-			delete(this.hc.userSIDs, sid)
-			this.hc.processEvent(HubEvent{EventType: EVENT_USER_PART, Nick: oldNick})
-			handleNewUser()
-
-		} else if sidExists && oldNick == newNick {
-			// Updating existing user
-			this.hc.users[newNick] = *uinfo
-			this.hc.processEvent(HubEvent{EventType: EVENT_USER_UPDATED_INFO, Nick: newNick})
-
-		} else if !sidExists {
-			// User joined
-			handleNewUser()
-		}
-
 	case "IMSG":
 		// General message from the hub
 		if len(parts) < 2 {
@@ -450,14 +467,15 @@ func (this *AdcProtocol) handleHubInfo(flags map[string]string) error {
 	return nil
 }
 
-func (this *AdcProtocol) handleUserInfo(flags map[string]string) (*UserInfo, error) {
+func (this *AdcProtocol) updateUserInfo(u *UserInfo, flags map[string]string) {
 
 	// User MyINFO
 	// BINF GUPR IDFEARIFD33NTGC4YBEZ3UFQS5R4ZXXTFL2QN2GRY PDZMIFLG5EKZG3BDRRMIJPG7ARNA6KW3JVIH3DF7Q NIivysaur5 SL3 FS3 SS0 SF0 HN1 HR0 HO0 VEEiskaltDC++\s2.2.9 US2621440 KPSHA256/3UPRORG4BLJ4CG6TO6R3G75A67LXOGD437NALQALRWJF6XBOECTA I40.0.0.0 U418301
 	// BINF GUPR I4172.17.0.1 U418301 IDFEARIFD33NTGC4YBEZ3UFQS5R4ZXXTFL2QN2GRY VEEiskaltDC++\s2.2.9 SF0 NIivysaur5 SL3 HN1 HO0 KPSHA256/3UPRORG4BLJ4CG6TO6R3G75A67LXOGD437NALQALRWJF6XBOECTA HR0 FS3 SS0 US2621440 SUSEGA,ADC0,TCP4,UDP4
+	// Or maybe only incremental:
+	// BINF Z3BA HO1
 	// TODO
 
-	u := UserInfo{}
 	for prop, val := range flags {
 		switch prop {
 		case "ID":
@@ -511,12 +529,6 @@ func (this *AdcProtocol) handleUserInfo(flags map[string]string) (*UserInfo, err
 	} else if !hasAP && hasVE {
 		u.ClientTag, u.ClientVersion = this.getAPVEFromSingle(VE)
 	}
-
-	if u.Nick == "" {
-		return nil, fmt.Errorf("Malformed user missing nick")
-	}
-
-	return &u, nil
 }
 
 func (this *AdcProtocol) getAPVEFromSingle(term string) (string, string) {
diff --git a/TODO.txt b/TODO.txt
index e0c97bd..bd95b9b 100644
--- a/TODO.txt
+++ b/TODO.txt
@@ -2,7 +2,5 @@ NMDC:
 - Implement ZPipe ($ZOn)
 
 ADC:
-- Test that user info updates work
-     - they're incremental: BINF Z3BA HO1
 - Usercommands
 - ???